1. M.S.STEVE
Assistant Professor
Dept. of Mechanical Engineering
Amal Jyothi College of Engineering, Kanjirapally.

2. Definition of Power Plant
The assembly of equipments that produces
mechanical energy utilizing the available
energy source and converting it to electrical
energy is known as a power plant
M.S.Steve/ Assist. Professor/ Dept. of ME/ AJCE
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3. Classification
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Hydro-electric Power Plant
Thermal (Steam) Power Plant
Diesel Engine Power Plant
Nuclear Power Plant
Gas Turbine Power Plant
M.S.Steve/ Assist. Professor/ Dept. of ME/ AJCE
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4. Hydraulic Power Plant
 Plants used to produce electric power from water are
known as hydro electric power plants
 This Power plants utilize the potential energy and
Kinetic energy of water as the source of energy for
power generation.
 KE & PE of water is converted into mechanical power
by using prime mover
Hydraulic Turbines.
 This mechanical energy is used to run an electric
generator which is directly coupled to the shaft of the
turbine.
M.S.Steve/ Assist. Professor/ Dept. of ME/ AJCE
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5. Main Elements
Storage Reservoir – Natural or artificial.
Dam – Masonry dams, wooden dams, steel dams
Waterways – canal, penstock, tunnel
Control elements – gates, valves, trash rack etc
Surge Tank – additional storage space between
main reservoir and power house. Also controls
pressure variations from rapid changes in rate of
flow of water through penstock
o Power House
o Water Turbines
o Generator
M.S.Steve/ Assist. Professor/ Dept. of ME/ AJCE
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6. Hydraulic Power Plant - General
Layout
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7. M.S.Steve/ Assist. Professor/ Dept. of ME/ AJCE
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8. Advantages
• Operating cost is minimum compared to other
power plants as no fuel is used
• Low maintenance cost
• Man power required for the operation is low
• No air pollution and safety problems
• Rapid fluctuating loads can be served economically
• Life of more than 50 years.
M.S.Steve/ Assist. Professor/ Dept. of ME/ AJCE
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9. Disadvantages
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High initial cost.
Power generation not steady and reliable.
Long distance transmission required
Cost of power transmission high.
Long time needed for planning and
erection(10 to 15 years).
M.S.Steve/ Assist. Professor/ Dept. of ME/ AJCE
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10. Steam – Thermal Power
Plant
A Steam thermal power plant converts the
chemical energy of the fossil fuels (coal,oil,gas)
into mechanical/electrical energy
In India, coal using as the main fossil fuel.
M.S.Steve/ Assist. Professor/ Dept. of ME/ AJCE
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11. Main systems of steam thermal plant
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Fuel system – coal and ash circuit
Air and gas circuit
Feed water system
Cooling water system
Boiler House
Prime mover and Generator system
Control and Instrumentation System
M.S.Steve/ Assist. Professor/ Dept. of ME/ AJCE
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12. M.S.Steve/ Assist. Professor/ Dept. of ME/ AJCE
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13. Components of steam thermal
plant
Boiler
2. Steam turbine
3. Generator
4. Condenser
5. Cooling towers
6. Circulating water pump
7. Boiler feed pump
8. Economiser
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Super heater
Re heater
Air heater
Boiler chimney
Water treatment plant
Coal mill
Control room
M.S.Steve/ Assist. Professor/ Dept. of ME/ AJCE
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14. Advantages
• Less capital cost
• Construction time is low
• Power generation not dependent on nature’s
mercy
• Power plant can be located near industrial
areas, so transmission cost will be less
M.S.Steve/ Assist. Professor/ Dept. of ME/ AJCE
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15. Disadvantages
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Power generation cost is high
Part load efficiency is less
Fuel transportation and handling is difficult.
Pollution
Ash handling is difficult
Life time of 20-25 years.
M.S.Steve/ Assist. Professor/ Dept. of ME/ AJCE
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16. Diesel Engine Power Plant
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Utilizing diesel for the power generation.
Capacity of plant – 2 to 50 MW
Mostly used as a standby power plant
Uses – Small power capacity, for small
towns, continuous power generation, peak
load plant, mobile power plant
M.S.Steve/ Assist. Professor/ Dept. of ME/ AJCE
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17. Components
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Engine- generally a 2 stroke engine
Air supply system
Exhaust system
Fuel system
Cooling system
Lubricating system
Starting system- compressed air
system(20kgf/cm2)
• Governing system- varying fuel supply
M.S.Steve/ Assist. Professor/ Dept. of ME/ AJCE
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18. M.S.Steve/ Assist. Professor/ Dept. of ME/ AJCE
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19. Advantages
• More efficient for small capacity power generation than
thermal plant.
• Layout, design and construction of buildings and foundations
easier and less expensive
• Quickly started up and brought into service.
• Full automation possible at low capital cost.
• No problem of fuel handling and waste disposal
• Less space required
M.S.Steve/ Assist. Professor/ Dept. of ME/ AJCE
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20. Disadvantages
• Size is limited and very large capacities are not
possible.
• Life is very less.
• Generates heavy noise
• High repair and maintenance cost
• High lubrication cost
M.S.Steve/ Assist. Professor/ Dept. of ME/ AJCE
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21. Nuclear power plant
• Use atomic energy for power generation
• Heat energy liberated using nuclear reaction.
• Heat produced by 1 kg of uranium = Heat
produced by 4500 tones of coal.
M.S.Steve/ Assist. Professor/ Dept. of ME/ AJCE
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22. Types of conventional reactors
• Pressurized water reactor (PWR)
• Boiling water reactor (BWR)
M.S.Steve/ Assist. Professor/ Dept. of ME/ AJCE
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23. Conventional Reactor....
Pressurized water reactor
– The most safe and reliable technology available
– Ordinary water used both for coolant and moderator
– High pressure of 150atm used to prevent boiling inside the
reactor
– Using high pressurized hot water, steam is generated in
secondary loop (called steam generator)
– Thermal efficiency of about 30%
M.S.Steve/ Assist. Professor/ Dept. of ME/ AJCE
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24. Pressurized water reactor...
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25. Reactor systems used..1
• Pressurized water reactor
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M.S.Steve/ Assist. Professor/ Dept. of ME/ AJCE

26. Conventional Reactor....
Boiling water reactor
– Ordinary water used as both coolant and moderator
– Steam is directly generated inside the reactor core
– Pressure inside the reactor is around 75atm
– Thermal efficiency is about 35%
– But maintenance cost more than PWR
– Eg:- Tarapur Power station
M.S.Steve/ Assist. Professor/ Dept. of ME/ AJCE
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27. Boiling water reactor
M.S.Steve/ Assist. Professor/ Dept. of ME/ AJCE
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28. M.S.Steve/ Assist. Professor/ Dept. of ME/ AJCE
Reactor systems used..2
• Boiling water reactor
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29. Advantages
• More economical compared to thermal plants.
• No problem of fuel transportation, storage
and handling , ash handling
• Low man power required
• Cost of operation reduced.
• Less space occupied than thermal plant.
M.S.Steve/ Assist. Professor/ Dept. of ME/ AJCE
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30. Disadvantages
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Danger of nuclear radiation.
Disposal of radio active wastes
Part load operation is inefficient.
Capital cost of small sized plants is high.
M.S.Steve/ Assist. Professor/ Dept. of ME/ AJCE
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