A PRESENTATION ONpresented BY :-

Pratik gupta (eee 5TH SEM )

DR. C.V. RAMAN INSTITUTE OF SCIENCE &

TECHNOLOGY

Steam turbine

What exactly is the turbine?

Turbine is an engine that converts energy of fluid into mechanical energy

The steam turbine is steam driven rotary engine.

Principle of steam turbine:The steam energy is converted mechanical

work by expansion through the turbine.Expansion takes place through a series of

fixed blades(nozzles) and moving blades. In each row fixed blade and moving blade

are called stage.

WORK IN A TURBINE VISUALIZED

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Steam turbine:

• Widely used in CHP(combined heat and power) applications.

• Oldest prime mover technology

• Capacities: 50 kW to hundreds of MWs

• Thermodynamic cycle is the “Rankin cycle” that uses a boiler

• Most common types• Back pressure steam turbine• Extraction condensing steam turbine

Steam Turbine System:

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• Steam exits the turbine at a higher pressure that the atmospheric

Back Pressure Steam Turbine

Fuel

Figure: Back pressure steam turbine

Advantages:-Simple configuration-Low capital cost-Low need of cooling water -High total efficiency

Disadvantages:-Larger steam turbine

Boiler Turbine

Process

HP Steam

Condensate LP Steam

Steam turbine:

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• Steam obtained by extraction from an intermediate stage

• Remaining steam is exhausted

• Relatively high capital cost, lower total efficiency

Extraction Condensing Steam Turbine

Boiler Turbine

Process

HP Steam

LP SteamCondensate

Condenser

Fuel

Figure: Extraction condensing steam turbine

Steam turbine:

steam turbine and blades

STEAM TURBINE 500 MW

Generator rated speed 3000 rpm Generator manufacturer BHEL No. of bleedings 6 No. of bearings 7 No. of stages

HPT 17 (All Reaction) IPT 12x2 ( All Reaction) LPT 6x2 (All Reaction) Total 53

Inlet Steam Pr: 166 ksc Inlet Steam Temp: 540 Deg C

STEAM TURBINE 600 MW

Generator rated speed 3000 rpm Generator manufacturer Electrosila No. of bleedings 8 Length of the turbine 36.362 m No. of stages

HPT 17 ( 1st Impulse & rest Reaction) IPT 11x2 ( All impulse) LPT-1 5x2 ( All impulse) LPT-2 5x2 ( All impulse) Total 59

Inlet Steam Pr: 247 Ksc Inlet Steam Temp: 537 Deg C

Types of steam turbine:There are two main types 1. Impulse steam turbine2. Reaction steam turbine

Impulse steam turbine:The basic idea of an impulse turbine is

that a jet of steam from a fixed nozzle pushes against the rotor blades and impels them forward.

The velocity of steam is twice as fast as the velocity of blade.

Pressure drops take place in the fixed blade (nozzle).

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PRESSURE-VELOCITY DIAGRAM FORA MOVING IMPULSE BLADE

PES

VELOCITY

PRESSURE

TURBINESHAFT

DIRECTION OF SPIN

ENTRANCEHIGH VELOCITYSTEAM INLET

REPRESENTS MOVINGIMPULSE BLADES

EXITLOW VELOCITY

STEAM EXHAUST

PES 15

IMPULSE TURBINE PRINCIPLE

NOZZLE

STEAMCHEST

ROTOR

Reaction steam turbine:A reaction turbine utilizes a jet of

steam that flows from a nozzle on the rotor.

Actually, the steam is directed into the moving blades by fixed blades designed to expand the steam.

The result is a small increase in velocity over that of the moving blades.

PES 17

PRESSURE-VELOCITY DIAGRAM FORA MOVING REACTION BLADE

TURBINESHAFT

DIRECTION OF SPIN

ENTRANCEHIGH PRESSUREHIGH VELOCITYSTEAM INLET

REPRESENTS MOVINGREACTION BLADES

EXITLOW PRESSURELOW VELOCITY

STEAM EXHAUST

PRESSURE

VELOCITY

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REACTION TURBINE PRINCIPLE

PES

STEAM CHEST

ROTOR

Schematic diagram:

Problems in steam turbine:Stress corrosion carkingCorrosion fatiguePittingOil lubricationimbalance of the rotor can lead

to vibration misalignmentThermal fatigue

Thank you