PRESENTED BY : BHUMIT SOLANKI

(3023713044)4TH SEM

o NTPC sipat has total installed capacity : 2980 MW

o Stage 1 = 3 X 660 MW

o Stage 2 = 2 X 500 MW

o Stage 2 is based on "Super Critical Boiler

Technology "

o COAL SOURCE

> Dipika Mines of South Eastern Coalfields

Limited

o WATER SOURCE

> Hasdeo barrage

o “Supercritical” is the thermodynamic state where thereis no clear distinction between the Water and Steamphase in the Ranking Cycle.

o Water reaches to steam state at a critical pressureabove 22.1 MPa at 374 °C.

o This "critical point" is at the apex of the saturation lineon T-s coordinates.

o Above this pressure, the physical properties (density,compressibility, and Viscosity) change continuouslyfrom those of a liquid to those of a vapor.

Higher unit cycle efficiency (40 - 42%).

Lower heat rate and electricity generation cost is lower.

Lower water losses because no continuous blow down.

Reduced auxiliary power consumption.

Reduce carbon dioxide (CO2) emissions and provides carbon credit within the Rankine cycle.

1. Coal handling plant2. Pulverizing plant3. Draft fans4. Boiler5. Ash handling plant6. Turbine7. Condenser8. Cooling towers and ponds9. Feed water heater10. Economizer11. Superheater and Reheater12. Air preheater

TURBINEGENERATOR

HIGH TENSION WIRE

Train (coal) Track hopper Conveyer

beltMill

Conveyer belt

Pulverisation process

Coal Coal Coal

small piece of coal

small piece of coal

powderEdcoalboiler

steamTurbine Generator Electricity

Tiscon pipe with basalt

cutters

Ash dyke

Water dyke

Condensation process

Cooling tower

Storage tank

Demineralisation process

steam

Water

Water

Water

Water

Water

Water

ash + hot water

ash + hot water

Ventilator turbine

dry ash

dry ash

Wind pipes

Chimney Atmosphere dry ashdry ash

Shaft

A thermal power plant burns enormous amounts of coal. A 200MW plant may require around 2000 tons of coal dailyThe function of coal handling plant is automatic feeding of coal to the boiler furnace.

In modern thermal powerplant , coal is pulverised i.e.ground to dust like size andcarried to the furnace in astream of hot air. Pulverisingis a means of exposing a largesurface area to the action ofoxygen and consequentlyhelping combustion.

Pulverising mills are further classified as:1. Contact mill2. Ball mill3. Impact mill

• The circulation of air is caused by

a difference in pressure, known as

Draft.

• Draft is a differential pressure b/w

atmosphere and inside the boiler.

• It is necessary to cause the flow of

gases through boiler setting

• It may be –

1. Natural draft

2. Mechanical draft

• A boiler or steam generator is a closed vessel in which water under pressure, is converted into steam.

• It is one of the major components of a thermal power plant

• Always designed to absorb maximum amount of heat released in the process of combustion

Boilers are of two types-

1. Fire tube boiler

2. Water tube boiler

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%)

oAsh collected in hoppers is grinded by grinders and mixed with water and then sent to ash slurry house by using jet pumps.

oWhere it is collected in ASH PIT, from where it is pumped to ASH POND.

oHere there is also an auxiliary pump which is used for FLUSHING OFF blockages.

A steam turbine converts heat energy of

steam into mechanical energy and drives

the generator. It uses the principle that

steam when issuing from a small

opening attains a high velocity. This

velocity attained during expansion

depends on the initial and final heat

content of the steam. This difference b/w

initial and final heat content repesents

the heat energy converted into kinetic

energy.

These are of two types :-

Impulse turbine

Reaction turbine

Steam after rotating steam turbine comes to condenser.Condenser refers here to the shell and tube heat exchanger (orsurface condenser) installed at the outlet of every steam turbinein Thermal power stations of utility companies generally.

These condensers are heat exchangers which convert steamfrom its gaseous to its liquid state, also known as phasetransition.

The purpose is to condense the outlet (or exhaust) steamfrom steam turbine to obtain maximum efficiency and also to getthe condensed steam in the form of pure water, otherwise knownas condensate, back to steam generator or (boiler) as boiler feedwater.

o A condenser needs huge quantity of water to condense the steam .

o Typically a 2000MW plant needs about 1500MGallon of water.

oMost plants use a closed cooling system where warm water coming from condenser is cooled and reused

oSmall plants use spray ponds and medium and large plants use cooling towers.

oCooling tower is a steel or concrete hyperbolic structure having a reservoir at the base for storage of cooled water

oHeight of the cooling tower may be 150 m or so and diameter at the base is 150 m

The exhaust gases contain

large amount of smoke and

dust, which are being

emitted into atmosphere.

This possess a real threat to

the mankind as a health

hazards. Hence it has

become necessary to free

the exhaust gases from

smoke and dust. The

Electrostatic precipitator

utilizes electrostatic forces

to separate the dust particle

form the gas to be cleaned.

Flue gases coming out of the boiler carry lot of heat. An economiser extracts a part of this heat from flue gases and uses it for heating feed water. This use of economiser results in saving coal consumption and higher boiler efficiency

After flue gases leave economiser,

some further heat can be extracted

from them and used to heat incoming

heat. Cooling of flue gases by 20

degree centigrade increases the plant

efficiency by 1%.

Air preheaters may be of three types

Plate type

Tubular type

Regenerative type

S u p e r h e a t e r i s a c o m p o n e n t o f a s t e a m - g e n e r a t i n g u n i t i n w h i c h s t e a m , a f t e r i t h a s l e f t t h e b o i l e r d r u m , i s h e a t e d a b o v e i t s s a t u r a t i o n t e m p e r a t u r e . T h e s u p e r h e a t e r m a y c o n s i s t o f o n e o r m o r e s t a g e s o f t u b e b a n k s a r r a n g e d t o e f f e c t i v e l y t r a n s f e r h e a t f r o m t h e p r o d u c t s o f c o m b u s t i o n . S u p e r h e a t e r s a r e c l a s s i f i e d a s c o n v e c t i o n , r a d i a n t o r c o m b i n a t i o n o f t h e s e .

The Synchronous Generator is used to Generate power by

connecting the shaft of the Turbine to the shaft of the generator

which cuts the magnetic flux producing Emf.

The Generated Voltage will generally 11KV to 20 KV max.

The Generated Voltage is stepped up by connecting Step up

transformer and is transmitted and is also used for Auxiliary

purposes.

Super crit ical power plants are the efficient plants to produce greater out put although it has some drawbacks……