Ntpc (national thermal power corporation) sipat mechanical vocational training report 4 haxxo24 i~i

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

CERTIFICATE

This is to certify that Mr. Harshit Kumar Gupta Of PDPM 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 project under my guidance.

Under the guidance of :-

Mr.M.C.Mitra

Sr.Supdt.(CHP/MM)

ACKNOWLEDGEMENT“It 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 would not 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, alwaysguided 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 VocationalTrainees.

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

Thanking You,

Harshit Kumar Gupta

POWER PLANT FAMILRISATION

NTPC SIPAT

660MW X 3 , 500MW X 2

“Salient features of NTPC Sipat” For 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 completed in 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 3785.18

crores. 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 coal transportation is carried on by MERRY GO ROUND system between the two projects. This is to avoid transportation discrepancies and for the smooth functioning of the plant.

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

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

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

COAL

HANDLING

PLANT (CHP)

CHP MAINLY CONSISTS…

• TRACK HOOPER• PADDLE FEEDER• CONVEYER BELT• MAGNETIC SEPRATOR• CRUSHER HOUSE• VGF• TRANSFER POINTS• STACKER• STOCKYARD/COAL PILES

• 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

PADDLE FEEDER

• Then this raw coal is scooped onto the conveyer by use of PADDLE FEEDER

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 the coal laden conveyor belt glides |~|

TYPICAL CONVEYER BELT…

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 POINTS through CONVEYER BELT.

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

OPERATION OF STACKER…

• Luffing : This is vertical movement ,powered generally by 2 hydraulic cylinders

• Traveling : The stacker moves on a rail track enabling 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 where required. This utilizes sun and planet gear type gear box

A TYPICAL STACKER....

BOILER

OR

STEAM GENERATOR

IT MAINLY CONSISTS THESE SYSTEMS…

• Fuel Preparation System

• Air & Flue Gas System

• Water & Steam System

• Fuel Firing System

• Deareation & Feed Pumping System

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

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 Slurry Pump) house

WATER AND STEAM SYSTEMMAINLY CONSISTS ….

• Boiler Feed Water Pump(BFW PUMP)-which pumps boiler feed water to ECONOMISER pressure.

• ECONOMISER –preheats 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 )

SUPER HEATERS…• Then separated saturated steam is taken out from boiler

drum 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

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

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 furnace from all corners leading to formation of fireball.

•

• 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:

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 used CLOSED TYPE HEATERS others are OPEN HEATER

• FEED PUMP: It mainly pumps BFW coming out of deaerator to ECONOMISER pressure.

TURBINE

&

GENERATOR

• Sole purpose of turbine is to produce work by expanding steam from very high pressure to low condenser pressure.

• We mainly use three types of turbine here viz. 1 HP turbine, 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 for expanding 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 )

BASIC ASPECTS OF 500 MW STEAM TURBINE….

GENERATOR…

• Shaft rotated at very high RPM by TURBINE is then coupled to generator which converts rotating energy of shafts into electrical energy.

• During this process there is large amount of heat generation 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 transfer coefficient of any gas and for its low viscosity which reduces wind-age losses

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

CONDENSATION

AND

COOLING WATER UNIT

CONDENSATION UNIT MAINLY CONSIST OF…

• CONDENSER: which is a shell type heat exchanger in which 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 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

A typical COOLING TOWER looks like…

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 system are:-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%)

• 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 is pumped 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

ASPH

AshDyke

A.S. Pump