NTPC (National Thermal Power Corporation) Sipat Mechanical Vocational Training Report 4-Haxxo24 I~I

8/22/2019 NTPC (National Thermal Power Corporation) Sipat Mechanical Vocational Training Report 4-Haxxo24 I~I

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DECLARATION BY STUDENT

I hereby declare that work entitled Summer training project report,

Submitted towards completion of vocational training after second year

of B.Tech (MECHANICAL) at PDPM-IIITDM JABALPUR

comprises of my original work

pursued under the supervision of guides at NTPC Sipat.

The results embodied in this report have not been submitted to any

other Institute or University for the fulfillment of any other curriculum.

Harshit Kumar Gupta

MECH ENGG.(4TH SEM)

PDPM-IIITDM JABALPUR


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CERTIFICATE

This is to certify that Mr. Harshit Kumar Gupta OfPDPM

IIITDM JABALPUR has undergone vocational

training from 21-05-2012 to 18-06-2012 at NATIONAL

THERMAL POWER CORPORATION SIPAT (C.G.) in the

COAL HANDLING PLANT and has made the projectunder my guidance.

Under the guidance of :-

Mr.M.C.Mitra

Sr.Supdt.(CHP/MM)


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ACKNOWLEDGEMENTIt is not possible to prepare a project report without the assistance and encouragement of other people.This

one is certainly no exception

On the very outset of this report, I would like to extend my sincere and heartfelt obligation towards all the personages

who have helped me in this endeavor. Without there active guidance, help, cooperation and encouragement, I wouldnot have made head way in the project. First and foremost, I would like to express my sincere gratitude to my project

Guide Mr. M.C.Mitra.

I was privileged to experience a sustained enthusiastic and involved interest from his side .

I would also like to thank Mr. D.S.Patil, Mr. Sameer Ekka, Mr. A.K.Singh, who instead of their busy schedule, always

guided me in right direction to head and also helped me in understanding Coal Handling Plant.

Last but not the least, I would like to thank Mr. Pravin Patel, for the allotment in the C.H.P. Batch of Vocational

Trainees.

I would like to thank Employee Development Center for organizing and permitting the Vocational Training Program forus.

Thanking You,

Harshit Kumar Gupta


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POWER PLANT

FAMILRISATION

NTPC SIPAT

660MW X 3 , 500MW X 2


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Salient features of NTPC SipatFor the first time in the history of India, a thermal plant using Super Critical technology

is constructed. In addition to this a 765KV transmission system is used for the first

time in the country. The ultimate capacity of the plant was originally conceived as 3000MW. Thereafter,

Sipat project was reconfigured as follows:

Thus the implementation of the project started in June 2007. It was to be completedin two stages.

Stage 1: 3*660 MW

Stage 2: 2*500 MW

The estimated cost for stage 1 was 7860.20 crores and for the stage 2 were 3785.18crores. The coal source of this project is DIPKA Expansion project of SECL in Korba(CG). Total coal linkage in the system is 15.04 million ton/year. The coaltransportation is carried on by MERRY GO ROUND system between the twoprojects. This is to avoid transportation discrepancies and for the smooth functioningof the plant.

The water requirement for the plant is fulfilled from Hasdeo RBC, through 26 kmpipeline from Hardi Vishal.

The beneficiary states are Chattisgarh, Gujarat, Madhya Pradesh, Maharashtra, goa,Daman & Diu and Dadra & Nagar Haveli. |~|


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A THERMAL POWER PLANT

MAINLY CONSISTS OF. 1.COAL HANDLING UNIT.

2.BOILER or STEAM GENERATOR UNIT.

3.TURBINE & ELECTRIC GENERATOR UNIT

4.CONDENSATION AND COOLING WATER

UNIT

5. ASH HANDLING PLANT


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COAL

HANDLING

PLANT (CHP)


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CHP MAINLY CONSISTS

TRACK HOOPER

PADDLE FEEDER

CONVEYER BELT MAGNETIC SEPRATOR

CRUSHER HOUSE

VGF TRANSFER POINTS

STACKER

STOCKYARD/COAL PILES


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The function of a CHP is to receive, process, store &

feed the Coal bunkers consistently over the entire

life of the Power plant.

Coal is received from mines in the form of lumps, the

sizes varying from 100mm to 350mm,BOBR meaning

Bogie Open Bottom Rapid discharge unloaded in

TRACK HOOPERS .(Here it comes mainly from DEEPIKA MINES )

BOBR

TRACK

HOOPER


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PADDLE FEEDER

Then this raw coal is scooped onto the

conveyer by use of PADDLE FEEDER


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CONVEYER BELT

Now this conveyer belt moves forward and carries that

raw coal to CRUSHER HOUSE.

In between there are equipment likes METAL

DETECTORS, SUSPENDED MAGNETS which

separates coal from METALS which is not desirable in

the production and Non-ferrous materials like stones,

shells, wood etc. are removed MANUALLY

These belts are very strong and have steel cords inside.

There are Normal conveyor Idlers , they are the

supporting rollers for the conveyor belt on which thecoalladen conveyor belt glides |~|


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TYPICAL CONVEYER BELT


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CRUSHER HOUSE.

Here coal received from track hoopers is fed to

VGF(Vibrating Gizzle Feeder) which allows 20(+) size

coal to go to crusher and not allow 20(-) coal to go to

crusher where there size is reduced to 20(-)

-Here we use Roller hammer type crusher .

- And there are 4 COUPLING motors located

over springs for rotating the rollers.

-Then all 20(-) coal is sent either to STOCK

YARD or to COAL BUNKERS

via appropriate TRANSFER POINTSthrough CONVEYER BELT.


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STACKER!!!! AND STOCK

YARD Coal stocks are made to meet needs in future

emergency situations.

Stacking/ reclaiming of coal is done by bucket wheel

type stacker-cum-reclaimer moving on rails.

The stacker-cum- reclaimer can stack coal on either

sides of the yard conveyer

During stacking mode coal is fed from conveyors on

boom conveyor and while in reclaim mode,

boom conveyor discharges coal on the yard conveyor for

feeding coal to bunkers through conveyors and transfer

points.

Note always water sprinklers are used to avoid fire in

COAL PILES


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OPERATION OF STACKER

Luffing : This is vertical movement ,powered

generally by 2 hydraulic cylinders

Traveling : The stacker moves on a rail trackenabling it to move around the stockyard as

required.

Slewing: This is rotation of the stacker around its

central axis to align or place the stockpile whererequired. This utilizes sun and planet gear type

gear box


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A TYPICAL STACKER....


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BOILEROR

STEAM GENERATOR


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IT MAINLY CONSISTS THESE

SYSTEMS Fuel Preparation System

Air & Flue Gas System

Water & Steam System Fuel Firing System

Deareation & Feed Pumping System


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FUEL PREPRATION SYSTEM

MAINLY CONSISTS. TRIPPERS: This is mechanism for dropping coals from

conveyer to BUNKERS .These only allows calculated

amount of coal to be dropped in all bunkers

COAL BUNKERS which stores coal mixture (20%

imported+ 80% Indian) and feeds this coal to

BOWL MILLS/PULVERISER where 20(-) coal is further

crushed to powder form having 200 meshes in 1 sq inch

There is SEAL AIR FAN for sealing of mill from dust.

PA FANS are used firstly to reduce moisture content,

secondly to heat it and lastly to transport powdered coal

to different corners of BOILER via 4 different pipes

.There are both COLD AIR DUT AND HOT AIR DUCT

TO MAINTAIN TEMP


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AIR AND FLUE GAS SYSTEM

MAINLY CONSISTS . FD fans provides sufficient air for combustion by taking

air from atmosphere and then heated by air

preheater(APH)

ID fans induces negative pressure in BOILER by

drawing out combustible gases

Flue gases generated by combustion contains quite imp

amount of heat which we utilise by sending it to

ECONOMISER and APH (to pre heat air) then cooled

flue gas is sent to ESP ESP (Electro Static Precipitator) where by corona

effect(cyclone separator) particles get precipitated over

electrode and flue gas escapes to atmosphere via

CHIMNEYS. Precipitate is sent to ASP(Ash SlurryPum house


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WATER AND STEAM SYSTEM

MAINLY CONSISTS . Boiler Feed Water Pump(BFW PUMP)-which pumps

boiler feed water to ECONOMISER pressure.

ECONOMISERpreheats BFW(all the sensible heating

of BFW is done here only)

****Then it goes to BOILER DRUM where saturated

steam get separated from mixed state steam by virtue of

cyclone steam separators and moisture content is again

circulated after mixing with BFW

NOTE-* implies that this unit i.e BOILER DRUM is not

found in SUPER CRITICAL BOILERS(as there is no

region inside dome according to MODIFIED RANKINE

CYCLE . So here water is always circulated only once )


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SUPER HEATERS

Then separated saturated steam is taken out from boilerdrum through series of nozzles and fed to series of

SUPER HEATERS.

Firstly through DIV PANEL SH-which heats saturated

steam by about 40 degree by mode of convection Then this passes through PLATEN SH-which raises

temp further by next 70 degrees by mode of radiation

then it goes to FINAL SH via ATTEMPRATOR which

lowers the temp by spraying a fine stream of water(it is

done to control the temp )

FINAL SH where remaining temp inc is picked up after

which it goes to HP turbine and get expanded

** All the superheaters used are basically CLOSED

HEATER


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REHEATERS. Sole purpose of reheating is to devoid wet steam from

condenser which may result in EROSION OF BLADES

of turbine.

After steam get expanded in HP turbine(upto IP say 345

degree and 45 bar) outlet steam is passed to

REHEATERS (after passing via another

ATTEMPRATOR) which heats up that steam

LT REHEATER and HT REHEATER:where temp is

raised upto temp of inlet of HP turbine


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FIRING SYSTEM MAINLY

INCLUDES Powdered coal is transported by PA fans to

corners of BOILER by 4 diff pipes(having same

pressure) and is blown TANGENTIALLY(to

imaginary circle called FIRE-BALL) in furnacefrom all corners leading to formation of fireball.


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Extra oxygen required for combustion is

provided by SECONDRY AIR

Initially during LIGHTING UP of boiler we

first ignite coal by HFO and HLT and stop

them after initialization

BURNER TILT MECHANISM:


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DEAERATION AND FEED

PUMPING SYSTEM MAINLY

CONSISTS DEAERATOR :whose main purpose is to remove air and

other gases from BFW (is mainly done otherwise they

may corrode different metals used in plant) and also to

preheat BFW . It is worth noticing that it is the only usedCLOSED TYPE HEATERS others are OPEN HEATER

FEED PUMP: It mainly pumps BFW coming out of

deaerator to ECONOMISER pressure.


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TURBINE

&

GENERATOR


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Sole purpose of turbine is to produce work by expandingsteam from very high pressure to low condenser

pressure.

We mainly use three types of turbine here viz. 1 HPturbine, 1 IP turbine and 2 LP turbine

We are using different pressure turbines for reheating

purpose so that we can enhance overall efficiency of the

plant (or so that we can overcome problem of wet steam) First superheated steam is allowed to expand in HPT to

some IP and then send back to boiler for reheating

purpose.

Then this reheated steam is sent to IP turbine forexpanding where after it get expanded to some lower

pressure a BLEND steam is taken out and sent to FEED

WATER HEATER (FWH) for heating feed water (for

REGENERATION )


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BASIC ASPECTS OF 500 MW

STEAM TURBINE.


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GENERATOR

Shaft rotated at very high RPM by TURBINE is thencoupled to generator which converts rotating energy ofshafts into electrical energy.

During this process there is large amount of heatgeneration for which we require a special type of cooling

system. Hydrogen gas cooling, in an oil-sealed casing, is used

because it has the highest known heat transfercoefficient of any gas and for its low viscosity whichreduces wind-age losses

This system requires special handling during start-up,with air in the chamber first displaced by carbon dioxidebefore filling with hydrogen. This ensures that the highlyflammable hydrogen does not mix with oxygen in the air.


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CONDENSATION

ANDCOOLING WATER UNIT

CONDENSATION UNIT


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CONDENSATION UNIT

MAINLY CONSIST OF

CONDENSER: which is a shell type heat exchanger inwhich exhaust steam is cooled by running cooling water

(circulated through tubes) and inturn CW gets heated

and is send to COOLING TOWER for getting cooled

Then this cooled water is extracted by CEP(Condensate

extraction pump) and heated by LPH and then to BFP

and then to HPH and then to ECONOMISER

COOLING WATER UNIT


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COOLING WATER UNIT

MAINLY CONSIST OF.. During cooling of steam CW gets heated and

this is send to COOLING TOWERS for getting

cooled.

Here hot CW is fed onto top of COOLING

TOWER and allowed to fall down

Also perpendicular to direction of falling air is

allowed to blow which cools the water and gets

out from top of the tower Also since always some of the water losts in the

whole process either due to leakage or due to

evaporation so we supply extra water from

MAKE UP WATER PUMP


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A t i l COOLING TOWER


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A typical COOLING TOWER

looks like


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ASH HANDLING PLANT .

Wherever coal is burned it is necessary to have an

efficient ash handling system, especially in a coal-fired

power station environment where large quantities of

pulverized fuel ash (PFA) are created

The various systems involved in the ash handling systemare:-Bottom ash handling system

-Fly ash handling system (both wet & dry)

-Slurry handling system from slurry pump house to ash dyke

-Ash water system

-Ash water recirculation system

Basically, two types of ash are generated:-Fly ash (approx 80%)

-Bottom ash (approx 20%)

A h ll d i h i i d d b i d d


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Ash collected in hoppers is grinded by grinders and

mixed with water and then sent to ash slurry house by

using jet pumps.

Where it is collected in ASH PIT, from where it ispumped to ASH POND.

Here there is also an auxiliary pump which is used for

FLUSHING OFF blockages. |~|

FLOW DIAGRAM OF AHP

Hopper

Clinker grinder

Scrapper

Conveyor

Overflow water

TrenchBA

Trans.

Pump

AS

Ash

A.S.Pump

Documents

NTPC (National Thermal Power Corporation) Sipat Mechanical Vocational Training Report 4-Haxxo24 I~I