The document discusses the basics of steam turbines. It explains that steam turbines convert the potential energy of high-pressure, high-temperature steam into kinetic energy and then mechanical energy. This mechanical energy can be used to drive rotating equipment. Steam turbines are preferred in process plants because waste heat from reactions generates high-pressure steam. The document describes the main types of turbines and compares impulse and reaction turbines. It also outlines key components, safety devices, starting procedures, maintenance checks, and losses within steam turbine systems.

1. BASICS OF STEAM TURBINES
PRESENTED BY
PREM BABOO
SR. MANAGER (PROD)
NATIONAL FERTILIZERS LTD.,INDIA

2. STEAM
TURBINES

3. WHAT IS STEAM TURBINE
STEAM TURBINE IS A DEVICE THAT
CONVERTS POTENTIAL ENERGY OF
HIGH PRESSURE , HIGH TEMPERATURE
STEAM INTO KINETIC ENERGY. THIS
KINETIC ENERGY IS SUPPLIED TO THE
ROTARY BLADE WHERE IT IS
TRANSFORMED INTO MECHANICAL
ENERGY.
THIS MECHANICAL ENERGY IS USED TO
DRIVE ROTATING EQUIPMENTS LIKE
PUMPS , COMPRESSORS , FANS ,
BLOWERS ETC.

4. WHY STEAM TURBINE PREFERRED IN
PROCESS PLANT ?
LOT OF STEAM IS AVAILABLE
AT HIGH PRESSURE AND
TEMPERATURE BECAUSE OF
RECOVERY OF WASTE HEAT
GENERATED AS A RESULT OF
VARIOUS EXOTHERMIC
REACTIONS TAKING PLACE IN
PROCESS.

5. ADVANTAGES OF STEAM
TURBINES
 THERMODYNAMIC EFFICIENCY IS MORE.
 DUE TO ABSENCE OF RECIPROCATING PARTS , THE
VIBRATIONS ARE GREATLY MINIMIZED AND THE
MACHINE CAN BE ACCURATELY BALANCED.
 NO RUBBING PARTS HENCE NO INTERNAL
LUBRICATION IS REQUIRED.
 ABOVE POINT ENSURES THE SUPPLY OF PURER
FEED WATER TO THE BOILER.
 LESS MAINTENANCE AS COMPARED TO OTHER
PRIME-MOVERS.

6. Steam Turbine
An Important Prime Mover in
Existence
Principle:
 The working of The Turbine wholly depends upon the
Dynamic Action of the Steam
 Steam is caused to fall in pressure in a passage
called NOZZLE
 Due to this a certain amount of heat energy is
concerted into MECHANICAL KINETIC ENERGY
 Steam is set moving with GREAT VELOCITY
 Rapidly moving steam enter the moving part of the
turbine & suffer A CHANGE IN DIRN. OF MOTION
 This leads to a CHANGE OF MOMENTUM &
THEREFORE TO A FORCE
 THIS CONSTITUTES THE DRIVING FORCES OF
THE MACHINE

7. STEAM INSTEAM OUT
FORCE
PRINCIPLE OF STEAM TURBINE

8. Types of Turbine
Based on Principle
Impulse Type
Pressure Compounded
Velocity Compounded
Pressure Velocity Compounded
Impulse Reaction Type

9. (I) SIMPLE IMPULSE:
The passage of steam through the moving part of the Turbine (Blade) may take
place in a manner that the pressure at the outlet side of the blade is equal to that at
the Inlet Side.

10. SIMPLE IMPULSE TURBINE IS NOT
SO COMMON
• SINCE THE WHOLE PRESSURE DROP TAKES
PLACE IN SINGLE ROW OF NOZZLES , THE
VELOCITY OF THE STEAM ENTERING THE
TURBINE IS VERY HIGH.IF THIS VELOCITY IS
UTILIZED IN SINGLE ROW OF TURBINE BLADES ,
THE SPEED OF ROTATION OF WHEEL WILL BE TOO
HIGH TO BE USEFUL FOR PRACTICAL PURPOSES,
AS THERE IS THE DANGER OF STRUCTURAL
FAILURES DUE TO EXCESSIVE CENTRIFUGAL
STRESSES.
• STEAM EXITS FROM THE TURBINE WITH
SUFFICIENTLY HIGH VELOCITY , MEANING A
CONSIDERABLE LOSS OF KINETIC ENERGY.

11. COMPOUNDING OF IMPULSE TURBINE
DEVELOPMENT OF STEAM TURBINES LEAD TO
COMPOUNDING WHEREBY SPEED OF
ROTATION IS REDUCED AND AT THE SAME
TIME FULL AVAILABLE ENERGY IS
UTILIZED.THIS ALLOWS PRODUCTION OF
TURBINES OF LARGER SIZE AND HIGHER
POWER OUTPUT. THIS IS ACHIEVED BY :
VELOCITY COMPOUNDING :- CONVERTING
THE TOTAL ENTHALPY FALL INTO K.E IN ONE
STAGE BUT DIVIDING THE CONVERSION OF
K.E OF STEAM INTO MECHANICAL ENERGY OF
THE WHEEL IN PORTIONS.

12. VELOCITY COMPOUNDING

13. ADVANTAGES OF VELOCITY
COMPOUNDING
•HAVE FEWER NUMBER OF STAGES HENCE
LESS INITIAL COST
•THE ARRANGEMENT RQUIRES LITTLE SPACE
•THE SYSTEM IS EASY TO OPERATE.
•THE PRESSURE DROP IN THE NOZZLE IS
CONSIDERABLE , SO THE TURBINE ITSELF
NEED NOT WORK IN HIGH PRESSURE
SURROUNDINGS AND THE TURBINE HOUSING
NEED NOT TO BE VERY STRONGLY MADE.

14. PRESSURE COMPOUNDING

15. COMBINED IMPULSE
TURBINE

16. REACTION TURBINE

17. IMPULSE VERSUS
REACTION TURBINES
*IN IMPULSE TURBINE THE FLUID IS COMPLETELY
EXPANDED IN THE NOZZLE AND IT REMAINS AT
CONSTANT PRESSURE DURING ITS PASSAGE THROUGH
THE ROTOR BLADES. IN REACTION TURBINE THE FLUID
IS PARTIALLY EXPANDED IN THE NOZZLE, THE
REMAINING EXPANSION TAKES PLACE IN THE ROTOR
BLADES.
*IMPULSE TURBINE HAVE THE SAME PRESSURE ON THE
TWO SIDES OF THE ROTOR BLADES, WHEREAS
DIFFERENT PRESSURE EXISTS ON THE TWO SIDES OF
THE MOVING BLADES OF A REACTION TURBINE.

18. IMPULSE VERSUS REACTION
TURBINES
*IMPULSE BLADES ARE OF THE PLATE OR
PROFILE TYPE AND ARE SYMMETRICAL ,
REACTION TURBINE BLADES ARE AEROFOIL
SECTION AND ARE ASYMMETRICAL.
*BECAUSE OF SMALL PRESSURE DROP IN EACH
STAGE , THE NUMBER OF STAGES REQUIRED
FOR A REACTION TURBINE ARE MUCH
GREATER THAN THOSE FOR AN IMPULSE
TURBINE.

19. RV.
T
LP Header
I/L
T
Condensate
I/L
COND
Classification Based on Exhaust
1) Back Pr. Type
2) Condensing Type

20. LOSSES IN STEAM
TURBINE
•RESIDUAL VELOCITY LOSSES
•LOSSES DUE TO FRICTION
•LEAKAGE LOSS
•LOSS DUE TO MECHANICAL
FRICTION
•RADIATION LOSS
•LOSS DUE TO MOISTURE

21. STANDARDS
API 611 : STEAM TURBINES FOR GENERAL
PURPOSE : DEFINED AS “ THOSE HORIZONTAL
OR VERTICAL TURBINE USED TO DRIVE
EQUIPMENTS THAT USUALLY IS SPARED,IS
RELATIVELY SMALL IN SIZE(POWER), OR IS IN
NON CRITICAL SERVICE.
API 612 : STEAM TURBINES FOR SPECIAL
PURPOSE : “THOSE HORIZONTAL TURBINE
USED TO DRIVE EQUIPMENTS THAT USUALLY
IS NOT SPARED,IS RELATIVELY LARGE IN
SIZE(POWER), OR IS IN CRITICAL SERVICE.

22. SAFETY DEVICES ON
TURBINES
 Emergency Governor: When Turbines speed
exceeds rated speed by approximately 10%, it trips
the unit
 Thrust Bearing Safety Device: Acts on high axial
displacement
 Low Lube Oil Pressure: Comes into action when
pressure falls below low pressure setting.
 Vacuum Device: Upon raising of Pressure in
condenser
 High Vibration: When vibration level goes high(up to
trip setting) turbine trips.

23. STARTING THE TURBINE
 Oil Supply
 Condensing System
 Opening the Live Steam Valve
 Opening of Emergency Stop Valve and Control Valve
 Bringing the Turbine upto Speed
 Speed Governor takes over
 Main Oil Pump takes over
 Automatic Oil Pump control
 Oil Cooling

24. DANGER SIGNALS
 Unusual Vibration
 Noisy Bearings
 Abnormally Hot Bearings
 Oil Rings not Turning
 Discoloured Oil
 Low Oil Pressure
 Excessive Gland Leakage
 Broken Lubricators
 Governor Hunting

25. PROTECTION SYSTEM
General Purpose Turbines
 Constant Speed Governor
 Over – Speed Tripping Device
 Relief Valve in Exhaust
 Casing Relief Valve
Special Purpose Turbines
 Low Lub. Oil Pressure Trip
 High Brg. Temp. Trip
 High Vibn. Trip
 High Axial Disp. Trip
 Const. Speed Governor
 Relief Valve in Exhaust

26. WHAT TO CHECK FOR IN
RUNNING TURBINES
 Noise Levels
 Leakage from Glands
 Vibration at Bearing Housings
 Bearing Temperatures
 Movement of Oil Rings of Sleeve Bearings
 Governor Oil Level (for Oil Relay Governors)

27. Principle Components of a
Steam Turbine
 Casing
 Shaft
 Blading (Moving and Fixed)
 Supports
 Bearings
 Governing System with Regulating Valves
 Shaft Sealing

28. FEW PHOTOGRAPHS