steam turbine power plant.pptx

7/28/2019 steam turbine power plant.pptx

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WELCOME


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STEAM POWER PLANT

A power plant in which the Water is heated,turns into steam and spins a STEAM TURBINEwhich drives an ELECTRICAL GENERATOR.After this ,the steam is condensed in aCONDENSER and recycled to BOILER.

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C

saturatedwater

hot gases

SteamTurbine

Gen

compressedwater

superheatedsteam

Condenser

Pump

cooling watersaturatedsteam

Steam Generator

Steam Turbine Power Plant

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Steam Turbine to produce Electricity

Oil could be usedinstead of coal.

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PRINCIPAL

All this process works on RANKINE CYCLE, a cycle that converts heat into work. It isnamed after William John MacquornRankine , a Scottish polymath and GlasgowUniversity professor.

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WHAT IS A RANKINE CYCLE ???

There are four steps in the Rankine cycle.Step 1-2 : The working fluid is pumped from low to high pressure.

As the fluid is a liquid at this stage the pump requires littleinput energy.

Step 2-3 : The high pressure liquid enters a boiler where it isheated at constant pressure by an external heat source tobecome a dry saturated vapor.

Step 3-4 : The dry saturated vapor expands through a turbine,generating power. This decreases the temperature andpressure of the vapor, and some condensation may occur.

Step 4-1 : The wet vapor then enters a condenser where it iscondensed at a constant temperature to become a saturatedliquid. 7


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TEMPERATURE VS ENTROPY DIAGRAM

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CARNOT CYCLE

The Carnot cycle is a theoretical thermodynamiccycle proposed by Sadi Carnot in 1824.It can beshown that it is the most efficient cycle for

converting a given amount of thermal energy intowork.

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CARNOT CYCLE VS RANKINE CYCLE

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PUMP

A device which transfers fluid from one placeto another place is called pump . Duringpumping process the pressure andtemperature of fluid increases.

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BOILER

A boiler is used wherever a source of steamis required. The form and size depends onthe application.

TYPESFire TubeDirect HeatingMulti-TubeWater Tube

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TURBINE

A steam turbine is a mechanical devicethat extracts thermal energy from

pressurized steam, and converts it intorotary motion.

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TYPES OF TURBINE

1- Impulse Turbine2-Reaction Turbine

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IMPULSE TURBINES

An impulse turbine has fixed nozzles thatorient the steam flow into high speed jets.These jets contain significant kinetic energy,which the rotor blades, shaped like buckets,convert into shaft rotation as the steam jetchanges direction.

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ROTOR

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IMPULSE TURBINE

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REACTION TURBINES

In the reaction turbine, the rotor bladesthemselves are arranged to form convergent nozzles. This type of turbine makes use of thereaction force produced as the steam acceleratesthrough the nozzles formed by the rotor. Steam isdirected onto the rotor by the fixed vanes of thestator. It leaves the stator as a jet that fills the

entire circumference of the rotor. The steam thenchanges direction and increases its speed relativeto the speed of the blades.

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ADVANTAGES OF STEAM TURBINE

It requires less space.Absence of various links such as piston, piston rod,cross head etc. make the mechanism simple. It is quiet

and smooth in operation,Its over-load capacity is large.It can be designed for much greater capacities ascompared to steam engine. Steam turbines can be built

in sizes ranging from a few horse power to over200,000 horse power in single units.

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ADVANTAGES OF STEAM TURBINE (CONT.)

The internal lubrication is not required in steamturbine. This reduces to the cost of lubrication.In steam turbine the steam consumption does not increase with increase in years of service.In steam turbine power is generated at uniform rate,therefore, flywheel is not needed.It can be designed for much higher speed and greaterrange of speed.The thermodynamic efficiency of steam turbine ishigher.

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CONDENSER

The device which converts vapors into liquidform called condenser .In steam power plants it is used to convert lowpressure steam into water by exchanging heat.The mechanism may be explained as :

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THANK YOU

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steam turbine power plant.pptx