A Project Report on

STUDY OF THERMAL POWER PLANT

UDUPI POWER CORPORATIONLIMITED

2*600MW

Submitted By

Aquib Nadaf

Department of Electrical and Electronics Engineering

National Institute of Technology Karnataka, Surathkal

ACKNOWLEDGEMENT

It is an immense pleasure for me to complete the report on Industrial Training in UPCL for a

duration of 15 days from 15/5/15 to 28/5/15. I express my deep respect & gratitude towards the

invaluable guidance, enormous assistance & excellent cooperation extended to form every

corner of the knowledge.

UdupiPowerCorporationLimited

The 2 x 600 MW Udupi Power Project is located in Udupi District of Karnataka, about 35 km

north of Mangalore city. The area was declared as industrial by the state in 1995 and 1998. The

nearest seaport is at Mangalore (New Mangalore Port Trust) and the project is well connected by

rail and road.

Each unit of 600 MW capacity has one sub-critical coal-fired steam generator connected to a

reheat type condensing steam turbine and generator with sea water cooled condenser and all

other required auxiliaries. Each steam generator is rated to generate about 2,028 tonnes/hour of

superheated steam at a pressure of about 175 kg/cm2 and superheat temperature of 540 C. The

steam generators are equipped with facilities for Heavy Fuel Oil/Light Diesel Oil (HFO/LDO)

firing for startup and flame stabilisation at low loads.

Each steam turbine operates at 3,000 revolutions per minute (rpm), tandem compound, single re-

heat, condensing type machine with extractions for regenerative feed water heating. The turbine

will be designed for main steam pressure of 170 kg/cm2 and inlet temperature of 5370C. The

fuel for power generation coal is imported from Indonesia and Africa and the platstotal annual

requirement is projected at 3.64 tonnes. HFO and LDO for startup are sourced from the Indian

Oil Company depot in the region.

Sea water for the condenser cooling water system is obtained from the sea coast 6 km away. A

re-circulating type natural draft cooling tower has been installed, and the sea water is returned

after cooling in the cooling towers. A desalination unit meets the fresh water and demineralised

water requirements of the plant.

Bottom ash is planned to be collected in silos in moist form and fly ash in dry form from the

electrostatic precipitator and stored in silos. Fly ash usage is envisaged for cement manufacture,

and unutilised fly ash and bottom ash are planned to be disposed at the identified ash disposal

area.

The power generated will be evacuated at two levels: 220 kV and 400 kV. A 400 kV

transmission line connects the UPCL substation to the Power Grid Corporation of India Limited

(PGCIL) substation at Hassan, 180 km away. A 220 kV transmission line connects the UPCL

power plant to the substation at Kemar, 25 km away, to cover local loads.

Environment Protection

The plant has a 275 m chimney with a biflue stack inside, a flue gas desulphurisation plant to

control sulphur, and low NOx burners to mitigate NOx emissions. The plant has high efficiency

electrostatic precipitators to limit the suspended particulate matter (SPM) within the prescribed

permissible limits. The coal and ash storage area in the ground is provided with impervious

layers to avoid contamination, if any. Quality Assurance

Coal Handling Plant

Coal handling is most important part of fuel management of a Thermal Power Plant where a

lot of money is invested in purchasing a high quality coal and care is to be taken reduce

production cost by using minimum fuel including transportation losses for producing one

unit of Power.

In UPCL, 2*600 MW, coal is imported from countries like Indonesia and South Africa

through water ways.

For a Cargo ship, it can carry coal up to of 70,000 to 90,000 Tons. In a month,

approximately 5 to 6 ships are unloaded for UPCL Plant. A total of approximately 3.2 to 3.5

lakh tons of coal is consumed by the plant in a month.

From New Mangalore Port Trust (NMPT) with the help of Southern Railways and Konkan

Railways, the coal is transported to the plant by Bogie Bottom Open Rapid Discharge

Railway wagons.

MAIN COMPONENTS OF CHP

Track Hopper:

Place where coal is unloaded from railway wagons. Here bottom discharge box is used.

It has Pneumatic cylinder which requires an air pressure of 6.3 bar for opening and

closing of bottom doors of the wagon. This air pressure is supplied by air compressors

present beside the track hopper.

Paddle Feeder:

There are 2 no’s of paddle feeder to feed coal to two conveyor belts 1A and 1B from the

track hopper. The paddle feeder has got a load to measure the flow of coal. This can be

adjusted by the operator to control the flow of coal on the conveyor belt.

CHP LAYOUT

Mainly there are 3 modes of operation in coal handling.

They are:

Mode 1 - Track Hopper to Bunker.

Mode 2 - Track Hopper to Stacker 1 or Stockyard to Reclaimer 1.

Mode 3 - Track Hopper to Stacker 2 or Stockyard to Reclaimer 2.

The BRDBO (Bogie bottom open rapid discharge wagon) is unloaded in the track hopper.

The unloaded coal is further fed to conveyors 1A and 1B through paddle feeders

As this coal is of above 50mm size, coal is sent to bunkers through conveyors 2A, 2B, JT 2,

3A, 3B.

After crushing up to 25mm size, the coal is sent to bunkers through conveyors 5A, 5B, JT8,

JT9, 9A, 9B in mode A.

For stacking and reclaiming operations coal is sent to coal yard or reclaimed from there

respectively.

During stacking operations coal is sent through 4A, 4B, 6A, 6B, JT3, RYCI and coal yard or

6A, 6B, JT4, RYC2. RYC1 and RYC2 are reversible and for reclaiming operations the coal

is reclaimed from the coal yard through RYC1 and RYC2 to JT3 or JT4 to JT6 to JT7, 7A,

7B to bunkers.

There are 6 bunkers for each unit in which under full load 5 bunkers will be under operation

and the 6th bunker will be in standby.

The coal is fed to the bunkers through the travelling tipplers.

Layout of CHP in UPCL

CRUSHER HOUSE

3A, 3B conveyors belt take the coal to the top of the crusher house >50mm. For this purpose

a HT motor is used of 11 KV. It is further connected to driving pulley through scoop

mechanism.

The coal enters through the ILMS where the iron pieces are removed and thrown out of the

conveyer belt from the coal.

Another set of ILMS is present at JT7. Pent house contains metal detector which detects

metal parts. 4A and 4B are reversible belt and can be used for both bunkering and stacking

operations.

STACKER/RECLAIMER

UPCL Plant has got 2 stacker/reclaimer one between CY1, CY2 and the other between CY2

and CY3.

The RYC1 and RYC2 has got 2 LT motors at their ends running at exact equal speed.

In case of stacking operation, the RYC1 lifts up the coal into the machine then to

intermediate conveyor and then to boom conveyor and then to coal yard. In this case, the

bunkers remain idle.

In case of reclaiming operations, the coal from coal yard if lifted by rotating buckets in the

coal heap and coal is cut in benches. The coal heap can be trapezoidal or conical. The coal

lifted by the buckets fall down on the boom conveyors and then transferred to RYC1 and

RYC2.

RYC1 and RYC2 is also called Long Travel conveyor.

To move the sleeve right or left, sleeve drive is provided and it is rotated by 2 no’s sleeve

wheels

using 2no’s of meters.

ELECTRICAL MOTORS USED IN STACKER/RECLAIMER

Bucker wheel 75 KW ABB

Intermediate conveyor motor 55 KW ABB

Boom Conveyor motor 55 KW, ABB

Vibro feeder motor 22 KW, ABB

Long travelling motor 5.5 KW, ABB

And dry type Transformer of 11KVA/50KVA is used.

COAL FEEDER AND BUNKERS

The coal comes to the bunkers through long conveyors 8A, 8B and these conveyors are

again driven by HT motors of 11KV.

The coal is then enters the bunkers through conveyors 9A, 9B. The travelling tippler fills the

bunkers as per requirement.

In this plant, each unit has got 6 bunkers. Capacity of bunker is 660 tones.

From the bunker, coal is fed to coal mill through gravity metric coal feeder.

For removing coal dust, the top of the bunkers are provided with Dust Extraction System

and exhaust fans.

COAL MILLS:

There are 6 no. of coal mills provided for each unit out namely A, B, C, D, E & F of which

5 of them will be running at full load and 1 will be in standby.

SAFETY SYSTEMS AND EMERGENCY

Pull Chord:

In case of emergency or hazard, pull chord can be operated by the operator to

immediately stop the conveyor. Pull chord wire runs throughout the conveyor.

Belt sway switch:

If the belt is running out of axis, it is sensed by the Belt Sway switch and the belt is

stopped.

Zero speed switch:

Zero speed switches sends a pulse signal depending upon the speed of the conveyor. If

the speed of conveyor is zero due to any reason, the zero speed gets activated and trips

the machine.

Since coal is a combustible element, it can easily catch fire. Auto fire detection systems are

provided through out the conveyor belt which is provided with a cable wire. If the cable

wire burns, then the water immediately flushes through the pipe and extinguish the fire.

COAL ANALYSIS

GCV of Indonesian coal is 5400 to 6400 kcal/kg.

UPCL requires 6000 tons per day to produce 600MW of Power for each unit.

Indonesian coal has a moisture content of 15%. Ash content of 2 to 12%. Volatile Matter

40%.

There are 2 types of analysis of coal a) Proximate analysis

b) Ultimate analysis

Ultimate analysis is not done in the plant. It is to be done before setting up of the plant as

the capacity and structure of the plant.

a) Proximate analysis: Proximate analysis of coal is done to find

1) Total Moisture

2) Ash

3) Carbon fixed

4) Volatile matter

5) GCV of coal

b) Ultimate analysis: In this analysis we fine the percentage of Calcium, Sulphur, Nitrogen,

Hydrogen and Oxygen.

FLUE GAS DESULPHURIZATION

One of the major constituents of flue gas is Sulphur oxides and Nitrous oxides. Sulphur

oxides when mixes with moisture in air below dew point (around 100degc) it forms H2SO4.

The Sox, NOx when reacts with atmosphere, it may pollute the atmosphere.

In order to prevent this happening both the units of UPCL are installed with

Desulphurization plant which remove sulphur from the flue gas not completely but to

acceptable limits.The desulphurization plant mainly consists of scrubber units technically

called as absorber.Absorbers are connected through a duct to the main flue gas path after the

ID fans and before the chimney.

Booster fans are connected in parallel to the flue gas path to absorb part of the flue gas

from which sulphur is removed. Booster fans have got blade pitch control to control the flow

of flue gas to absorber.The absorber units are provided with limestone storage tanks.

Limestone is basic in nature; it reacts with sulphur which is acidic in nature and neutralizes

forming Gypsum.

CaCO3 + SO2------------CaSO3+CO2

½ 02+CaSO3+2H20-----------CaSO4+2H2O

In the absorber, limestone powder has to be fed from the top of it, but limestone is received in

the form of solid lumps which has to be crushed.

VFD weigh Belt feeder is provided below the limestone silo in order to weigh the lime

consumption. After the belt weight feeder the lime stone falls on a reversible belt where it can

be fed to ball mill 1 or 2.

Hydro cyclone works on the principle of cyclone precipitators where heavy particles

settle down and lighter particles raises upwards.

After hydro cyclone, the lime slurry with water in the slurry recirculation tank and this

slurry water is fed to the absorber which falls down the top and flue gas enters from the

bottom.

gas with Agitations are provided at the bottom of the absorber to provide thorough

mixing of flue lime slurry.

Oxidation blowers are provided to give extra O2 to form gypsum and to remove air from

gypsum. The gypsum formed at the bottom of absorber is in liquid state and to make it to solid

state vacuum belt fitter are provided.

Temperatures inside the absorber are continuously monitored. Temperature should not

exceed above 100degc as the internals of the absorber are made up of rubber. If temperature

exceeds above normal level, water is flushed through quenching spray to reduce temperatures.

ASH HANDLING PLANT

BOTTOM ASH HANDLING

There are 4 bottom ash hoppers for each unit. Whenever there is steam blowing inside the

boiler the bottom ash falls on the refractory walls and then to bottom ash hoppers.

The bottom ash hoppers are immersed in seal trough to avoid ingress of air into the boiler

in order to prevent disturbance to boiler draft. The bottom ash lumps fall on to the scrapper

conveyor which is run by chains and pulley.

Each unit has got two scrapper conveyors out of which one will be running and the other

will be in standby.

The bottom ash from scrapper conveyor is carried forward to the clinker grinder where

the bottom ash lumps are grinded and carried forward on a belt conveyor to bottom ash storage

bin when the ash is disposed to the ash dyke with the help of trucks. The ash slurry from

scrapper conveyor overflow comes and falls in drain sump.

The water from drain sump is recovered and re used again. For that purpose, we have

settling tank and surge tank.

Settling tank separates ash, water and surge tank collects the separated water.

ECONOMIZER ASH HANDLING:

After Economizer, there is a bend in duct of the boiler furnace and then flue gas goes to

air pre heater.

As ash travelling in this path and due to a sudden change in its path, the ash tries to settle

down due to gravity.

At this path, 7 hoppers are provided for each unit to collect economizer ash.

Each economizer hopper is provided with a manual gate and solenoid gate to open and

close. The hopper’s end is enclosed in a seal trough to avoid ingress of air into boiler furnace

to avoid disturbance to boiler furnace.

The economizer ash reaches the scrapper conveyor where the next process is all same as

in the case of bottom ash handling. After seal trough the economizer ash is sprinkled with

water in the flushing apparatus.

FLY ASH HANDLING

Fly ash is totally collected in “Electro static precipitator”. The ESP contains a cathode

and anode in every field which are supplied with a DC voltage of 60KV.

When the ash particles enter the ESP fields, they get negatively charged and gets pushed

away from the cathode as like charges repel. The ash particles get attracted by the anode walls

which are positively charged. The ash particles are uniformly distributed to each ESP Field by

a Gas Discharger Plate. Thus clean flue gas moves out from the ESP outlet. The efficiency of

ESP is 99.7%.

To avoid fouling of the anode, cathode and gas discharger of ESP by the ash particles,

emitting electrode rappers, collecting electrode rappers and gas discharger plate rappers are

provided.

After rapping of the electrodes the ash is finally collected in the ESP hoppers which are

transported to the Buffer Hopper by 3 vacuum pumps out of which 2 vacuum pumps are

generally in running.

The buffer hopper consists of a bag filter to which the ash gets deposited. The ash

particles fall down in the buffer hopper by giving a puffing of Instrument Air of 6 bar which

are then moved to ALU.

The fly ash is collected in the Air Lock Vessel (ALV) is transmitted to Ash Silo as air +

ash mixture with the help of 3 no’s of TAC (Transport Air Compressor) having a pressure of

2.5 to 3 kg/cm2.

ASH SILO

For fly ash disposal system, there are 4 Silos constructed far away from the main plant.

The fly ash which is collected in the ESP is transferred to the Silo with the use of 3Transport

Air compressor (TAC).Each Silo has got a height of 16mts. Each meter can store up to 90 tons.

Thereby the capacity of each silo is 16*90=1440 tons. Total capacity of 4 silos is 5760 tons.

Bag filter is installed at the top of the silo. Three Pneumatic valves for 3 pipe lines (2 for

two units each and 1 is common) is installed at the top of the silo. Purging of Bag filters is

done at regular intervals.

Vent fans are provided to remove compressed air and to maintain vacuum.

Aeration blowers are provided at the bottom of the silo which blows air through fluidized

bed in order to level the fly ash and prevent choking of silo.

The bottom of the silo is provided with pneumatic gate and paddle feeder and volumetric

feeders to load the fly ash through chute provided at the bottom of the silo. Scavenging air fan

is provided to maintain the vacuum in the chute. The ash collected in the Ash Silo is moved out

of the plant by ash carrying trucks to the Ash Dyke or to the cement manufacturing companies.

5. SEA WATER INTAKE PUMP HOUSE

Raw water is taken from the Arabian Sea with the help of gravity by GRP pipelines into the fore bay which is of 7.5mts of depth. Sump is further divided into 4 canals.

The intensity of a water intake totally depends upon the wave intensity. For a high tide water intake will be more and low tide water intake will be less.

4 stop gates for two intake pipelines are provided to stop the water intake if necessary. Cleaning/maintenance can be done at this time.

There are 2 pipe lines provided to mix chlorine water in the sump water for chlorination in order to reduce turbidity. 2 gates are provided to stop chlorination.

There are 3 no’s of 11KV intake pumps which pumps water to the balancing sump and NDCT in the plant and the water is further sent to clarifier. Under normal condition 1 pump will be running and 2 pumps will be in standby. The flow through the pipe will be 5500m3/hr. The pump runs with a pressure of 4 kg/cm2.

Before the pump intakes water there are travelling screens present in the way which will stop the entry large size particles like dust/fungus, plastic, fish, prawns, grass etc. A back flush jet is provided to clean the travelling screens. The dust is all collected in a separate drain tank. Cleaning of screens is done for 20 minutes in a shift.

There are certain permissive for a pump to start like thrust bearing temperature, winding temperature, current sump level, NRV open and flow in the pipe etc.

There are total 3 no’s of intake pipes (2GRP, 1MS)and 2 no’s of return drain pipe from and to the sea from the main plant.

6. CW AND ACW PUMP HOUSE

6.1 CW PUMP HOUSE

CW pump specifications:

Pump output flow: 35300m3/hr

Input voltage: 6.6kv

Power: 3000kw

Speed: 372 rpm

Discharge pressure: 2 to 2.3 kg/cm2

Header pressure: 2.7 kg/cm2

In order to refresh, the cooling water is blow down is provided and at the bottom of the sump and fresh water is added as make up.

In order to treat sea water and reduce algae, chlorination is done for sea water.

6.2Chlorination Plant:

For chlorine dozing, the sea water is taken from CW pump outlet normally. Two sea water pumps are also provided for this purpose.

The sea water then moves on to 4 no’s of Electrolyzes out of which 2 no’s of Electrolyzes will be in running.

The Electrolyze will be consisting of one cathode and one anode and it is supplied with a dc voltage of 135V and current of 750 A. 4 no’s rectifier cubicles are present for this purpose.

The sea water then moves on towards 4 no. of Electrolyzes out of which 2 no. of Electrolyzes will be in running and 2 no. will be in standby.

The Electrolyzes will be consisting of one cathode and one anode and it is supplied with a dc voltage of 135V and with a current of 750A with the help of 4 no. of Rectifier cubicles one of each Electrolizer.

Nacl+H2O NaOH+HCl

NaOH+HCl NaOCl+2H+

Sodium Chloride (NaCl) is present in sea water. In Electrolizer NaCl reacts with H2O & forms NaOCl solution which is called HYPO. This HYPO solution is stored in a 50 KL capacity tank.

This solution can be dozed to sea water with the help of 2 no. of NaOCl pumps out of which one is kept in running and one is kept in standby normally as per requirement.

Some of salts which are deposited on the electrode plates of Electrolizer are cleaned by flushing HCl acid which is pumped using 2 no. of acid pumps and blowers are provided to form Hydrogen ions by blowing adequate air.

6.3ACW PUMP HOUSE

The Auxiliary Cooling Water used for cooling of Turbine/ Boiler Auxiliaries is also sea water taken from the CW fore bay. There are 3 no. of ACW Pumps out of which normally 2 are in running and one is in standby. The ACW inlet contains a strainer.

ACW Pump Specifications:

Power - 449.4KW

Voltage - 6.6KV

Speed - 1490 rpm

TDH - 52.4mm

No. of stages - 1

Balancing sump depth - 3.7 mtrs

GUARD POND:

The waste water or return water from DM plant, BOP, Boiler, CW sump are collected here and this water should be sent to disposal, into sea. For this, there are 5no’s of pumps out of which 2 are running normally and 3 no’s of pumps are standby.

Guard pond Pump specifications: Motor details:

Make: Flow more limited Make: Marathon Electric

Pump input: 138.6KW Voltage: 415V, 50HZ

TDH: 21Mtr Capacity: 180 KW

Speed: 1485RPM Amps: 305A, RPM: 1485, PF: 0.86 Capacity: 2000m3/hr Efficiency: 95%

7. EFFLUENT TREATMENT PLANT

The main function of the ETP is to maintain the normal PH value of the waste water which can be left into the sea or for watering the garden which would otherwise it will be a problem to the environment.

For this purpose, the waste water is treated with ALUM and Limestone and turbidity is also reduced.

The waste water from Boiler side, CHP, AHP, DM plant, Ash Silo etc comes to ETP sump

where it is carried forward with the help of 3 pumps out of which normally 2 will be running

and one is standby.

After the water is taken out from the sump, the Alum and Limestone are added in the water

and this water reaches the flash mixer where Poly is added to reduce the turbidity.

The PH of the waste water should be around 6.5 to 8. The flash mixer contains a motor for rotating the mixing rod.

In the ETP sump, to remove the oil content from the water which settles at the top portion of water, always a pulley driven belt system is provided.

After mixing of water in flash mixer, the water is further sent to flocculator where the water is mixed gently with the stilling rod and the water further moves on to clarifier.

In the clarifier, water enters from the center of the clarifier tank and overflows to the outer tank through V notches and reaches the CMB sump finally. The sludge of the waste water is collected at the sludge tank.

There are two no’s of sumps provided at the CMB sumps ( 1W + 1S ) which are used for sending treated water to guard pond.

WATER TREATMENT PLANT & D.M. PLANT

Cascade Aerator:

Water from the sea water balancing sump is pumped to Cascade Aerator with the help of 3

no. of Clarifier feed pumps out of which one is working and the other is in standby. In

cascade aerator sea water is exposed to oxygen and ultraviolet radiation of sun in order to

improve taste and odor.

NaOCl is added to the sea water in cascade aerator for chlorination purpose to reduce algae formation. The chlorinated water moves forward to the stilling chamber.

Flow rate, maximum of cascade aerator is 2400 m3/hour and Number of steps in cascade aerator are 8.

Stilling Chamber:

The velocity of the water is reduced in the stilling chamber so that we can maintain stable water flow.

FeCl3 & PolyElectrolyte to be added in the path of stilling chamber and flash mixer.

FeCl3 is used to gather all small particles in water. Poly Electrolyte is used to gather all suspended particles present in the water. The capacity of stilling chamber is 20m3.

Flash Mixer:

Alum and Lime solution is dozed for coagulation through dosing pump. 1 no. of agitator is provided for proper mixing. The capacity of Flash mixer is 40 m3.

Clariflocculator:

2 no. of Clarriflocculator of circular type are provided with rotating bridge and suspended scrapper.

Clariflocculator is a combination of flocculation and clarification in a single tank.

It has 2 concentric tanks where the inner tank act as a flocculator and outer tank act as a clarifier.

In the clariflucculator, the water enters the flocculator where the rotating bridge improves the flocculation of the solids.

As heavy particles settle at the bottom, the liquid flows upwards in the clarifier zone. The clarifier discharges water over a peripheral weir into the peripheral launder.

The deposited sludge is settled at the bottom from where it is routed to the sludge sump and discharged to the sludge tank. Thus general service water is produced for drinking and other domestic purposes.

The normal feed flow through the Clariflocculator is 1050 m3/hr and maximum feed flow is 1200m3/hr.

Rapid Gravity Filter:

The water coming out of clariflocculator mixes with anthracite coal, gravel and sand for attracting the suspended particles for 24 hours in the Rapid Gravity Filter zone.

Air Blowers and flushing line are connected to the rapid gravity filters for cleaning filters.

The normal/ maximum feed flow of RGF is 400 & 500 m3/hr respectively.

Filter Water Reservoir:

After RGF filter water is stored in the reservoir. Then water moves forward to the pressure sand filter. The capacity of filter water reservoir is 5800 m3. The working pressure is ATM.

Pressure Sand Filter:

The 4 no of RO Make Up pump is used to pump water to the PSF out of which 3 are normally under running and 1 is in standby. The capacity of RO Make Up Pump is 710 m3/hr.

PSF consists of gravel and sand tightly packed up to 400mm and 900mm respectively. PSF allows only 20 microns particles to flow through it. Its output pressure is 4 Kg/cm2.

There are total 7 no. of PSF out of which 6 will be service generally and 1 is in standby. The flow of water through PSF is 325 m3/hr.

To clean the PSF a 3 No. of Backwash Water Pump are provided whose flow is 580m3/hr.

Micron Cartridge Filter:

Before MCF we are adding anti oxidant, HCL and sodium meta bisulphate. Sodium Meta

Bisulphate (SMBS) is used to remove chlorine. There are 3 no. of MCF provided. Flow of

MCF is 643m3/hr. No. of Cartridges are 161. Size of each cartridge is 100mm * 65 mm.

Sea Water Reverse Osmosis:

4 no. of High Pressure Pump is used pump water to SWRO whose flow is 643 m3/hr. There

is only 35% water permissive in the Sea Water Reverse Osmosis Filter. The remaining 65%

water is rejected through the ERT (Energy Recovery Turbine) reject line and goes to the

sludge sump.

3 no. of Energy Recovery Turbine with a pressure of 418 m3/hr is used increase the pressure

at the SWRO feed inlet by using SWRO reject water discharge pressure.

Degasser:

It works on the same principle as that of Deaerator. It is used to remove CO2 from the water. In the degasser tank gas flows through the bottom and water is sent through the spray type tray from the top side.

The sprinkled water comes in contact with gas so that CO2 is removed from water. Then the water moves to BWRO.

Back Water Reverse Osmosis:

There is only 20% water permissive in Back Water Reverse Osmosis Filter. The remaining

80% of water is sent back to the reject line to sludge sump. The permitted water moves to

mixed bed Filter.

Mixed Bed Filter:

Mixed bed filter contains cation and anion resins for removing cations and anions from the water.

For the continuous activation of resins we are adding HCL for cations and NaOH for anions.

DM Water Storage Tank:

After all the above process DM water is finally stored in 2 no. of DM Storage Tanks.

Sr. No.

1. pH of DM Water 6.8 to 7.1

2. Conductivity of DM Water < 0.2 us/cm

3. SiO2 < 10ppb

4. Total Dissolved Solids < 0.1 ppm

5. Capacity of each DM tank 1200 m3

6. Capacity of each DM Transfer Pump 3 no.s (2+1) 80m3/hr

DM Transfer Pump & Motor Specifications:

Sr. No Specification Details

1. Power 27.6 KW

2. Stator Voltage 415 V

3. No. of Pumps 2 W+1S

4. Frequency 50 Hz

5. Discharge Flow 80 m3/hr

6. Stator Current 65 A

7. Speed 1450 rpm

COOLONG TOWER

Cooling Towers for Refrigeration An important device used in any refrigeration or air conditioning system is a condenser. A

condenser is used in the high pressure side of a refrigeration or air conditioning system to

convert the high-pressure vapour refrigerant from the compressor into liquid refrigerant. The

medium used in a condenser may be water or air, depending upon the application. In the case of

water cooled condensers, the warm water being pumped by the condenser should be cooled with

the help of cooling towers so that the same water may be re-circulated to the condenser.

Principle of Operation for Cooling Towers The principle of operation of cooling towers is very similar to that of the evaporative type of

condensers, in which the warm water gets cooled by means of evaporation. Water evaporates as

a result of the hot water droplet coming in contact with the air (which is being pumped out by

means of a fan). This evaporating water also absorbs the latent heat from the water surrounding

it. By losing latent heat, the water is cooled.

SWITCHYARD

Electrical System in Power Plant

STEAM TURBINE GENERATOR SPECFICATIONS:

Sr. No. Specification Rating

1. Make DONGFANG Electrical Machinery Co. Ltd.

2. Rated Capacity 706 MVA

3. Rated Output 600 MW

4. Rated Stator Voltage 22 KV

5. Rated Stator Current 18,525 A

6. Rated Power Factor 0.85

7. Frequency 50 Hz

8. Rated Speed 3000 rpm

9. Rated H2Pressure 0.45 MPa

10. Maximum H2 Pressure 0.5 MPa

11. Winding Connection 2-Y

12. Cooling Water Flow of Stator Winding 96 m3/hr

13. Cooling Water Pressure of Stator Winding 0.20 MPa

14. Rated Field Current 4,727 A

15. Running Temperature 450 C

STATIC EXCITATION SYSTEM

The excitation supply is given to the field winding of the Turbo Alternator.

During start up, when there is no output from the generator, a large battery bank provides the

necessary power for excitation.

Once the generator output reaches 10% of the rated voltage, the excitation supply is tapped

from the output of the Turbo Generator terminals via excitation Transformer. This rectified

supply is fed to the rotor of the Turbo Alternator. AVR has a Voltage and Current feedback

from the generator terminal such that it can automatically maintain the machine to operate in

the permissible region of the Capability graph of the machine.

Excitation Transformer Specifications:

Sr. No. Specification Rating

1. HV side voltage 2400 KVA

2. Operating Frequency 50 Hz,1phase

3. LV side Voltage 900 V

4. Tapping -2 to +2 V *2.5%

5. HV Current 1890 V

6. LV Current 2666.7 A

7. Temperature 810 C

8. Present Temperature 52.80 C

9. Insulation Class F

10. Impedance Voltage 8.46%

Generator Excitation Specifications:

Sr .No Specification Details

1. Rated excitation voltage 431 V

2. Ceiling voltage of excitation system 1000V

3. Rated continuous excitation current 4727 A

4. Ceiling voltage for 20 seconds 8986 A

5. Response time 80 ms

6. Excitation Mode DC 220 V

7. Total power consumption of excitation cabinet 58 KW

400KV GT-1 Transformer Details:

Transformer capacity in MVA 250 * 3

Transformer total capacity in MVA 750

HV voltage rating in kV (primary) 420

HV current rating in A (primary) 1030.98

LV voltage rating in kV (secondary) 22

LV current rating in A (secondary) 19682.4

Rated Voltage in kV 420

Voltage at Maximum tap in kV 441

Voltage at Minimum tap in kV 399

Transformer % Impedance 14.8

OLTC Range +5% to -5%

Step 2.5%

Vector Group YNd11

400KV/220KV ICT#1 (R3A&R3B ) Transformer Details:

Power in MVA 315

HV side Voltage in kV 400

LV side Voltage in kV 220

HV side CTR Primary in A 2000

HV side CTR secondary in A 1

% Impedance 10.3

LV side CTR Primary in A 1600

LV side CTR secondary in A 1

Vector Group YNyn0

OLTC Range 10%

STATION TRANSFORMER-1: 220/11.5/6.9 kV, 63 MVA TRANSFORMER Details:

Power 63 MVA

HV side Voltage 220 kV

HV side CT Ratio 1600/1 Amps

LV1 side Voltage 11.5 kV

LV1 side CT Ratio 2500/1 Amp

LV2 side Voltage 6.9 kV

LV2 side CT Ratio 2500/1 Amp

% Impedance 25%

Vector Group YNyn0yn0

UNIT AUXILLARY TRANSFORMER (UAT): 22/6.9 kV, 25MVA Transformer Details:

Capacity 25MVA

HV side rating 22kV

LV side rating 6.9kV

Tap Range -10% to +10%

Tap Increment 1.25%

Vector Group Dyn1

High Voltage Switch Yard [400KV & 220KV]

400KV Switch Yard [One and Half Bus Bar Scheme]

In UPCL the power generated is supplied to two different Power grids. One of them is

400KV Southern India Power Grid and the other is 220KV Karnataka State Power Grid

Corporation.

The 400KV Switch Yard is a One and Half Bus bar Scheme and the main advantage of this

scheme is feeders will be intact in case of bus faults.

The transmission lines coming from PGCIL Hassan District in Karnataka are connected to

this Switchyard.

Each line and Bus Bar are provided with CTs and CVTs for the measurement of current and

voltages for metering and relaying.

220KV Switch Yard [Double Bus bar Scheme]

The 220KV switch yard is a Double Bus Bar Scheme in which two lines from KPTCL from

Kemmar Area in Karnataka are connected.

. There are 2 tapping provided for the station transformer which gives supply for all the

station auxiliaries.

Each station transformer has 2 LV windings, i.e. 6.6kV and 11kV. 6.6kV can feed Unit

auxillaries while lighting up the generator units. 11kV feeds station auxillary switch boards.