2. Steam Power plant is one of the main
sources of electrical energy.
It uses Steam as a working fluid.
It converts heat energy into mechanical
work by using steam turbine.
14. Power Generation and Plant Operation
Course Contents
Energy Sources, Steam Power Plants, Boilers, Condensers, Water
conditioning, Combustion, Cooling Water Supply, Turbines, Gas
Turbine , Nuclear Power Reactors, Steam Generators, Nuclear Safety
Generators, Sub-station equipments etc.
15. Energy Sources
• Fuels Solids – Coal, Coke, Anthracite etc.
Liquids – Petroleum and its derivates
Gases – Natural gas, blast furnace gas
• Energy stored in water
• Nuclear Energy
• Wind Power
• Solar Energy
• Tidal Power
• Geothermal Energy etc.
16. Fuels
A chemical fuel is a substance which release heat energy
on combustion. Carbon & Hydrogen are the principal
combustible elements.
Types of Fuel Natural Prepared
Solid Wood Coal , Coke
Peat Charcoal
Lignite Coal Anthracite
Liquid Petroleum Gasoline
Kerosene
Gaseous Natural Gas Coal Gas
Coke Oven
Blast Furnace
17. Solid Fuels
Coal – its main components are Carbon, Hydrogen Nitrogen,
Sulphur, moisture and ash. Pass through different stages like
Peat, Lignite – Brown Coal Semi-bituminous coal –
Bituminous Coal, Semi Anthracite – Anthracite
Properties of Coal :-
1. Energy Content of heating value
2. Sulphur Content
3. Burning Characteristics
4. Grindability
5. Ash
18. A good Coal should have:
i. Low ash content and high calorific value
ii. Small percentage of Sulphur
iii. Burning characteristics etc.
Grading of Coal:-
Grading is done on the following basis:
i. Size ii. Heating value
iii. Ash Content iv. Ash Softening temperature
v. Sulphur Content.
A grade written as (5 – 10 cm, 500-A8-F24-S1.6)
19. Liquid Fuels
Petroleum :- Heavy oil or crude oil is refined in
refineries, which gives most important product called
petrol. Composition of some liquid fuels is as under:-
Fuel Carbon Hydrogen Sulphur Ash
Petrol 85.5 14.4 0.1 -
Benzene 91.7 8.0 0.3 -
Kerosene 86.3 13.6 0.1 -
Diesel Oil 86.3 12.8 0.9 -
Light Fuel 86.2 12.4 1.4 -
Heavy Fuel 88.3 9.5 1.2 1.0
20. Important properties of Liquid Fuels
i. Specific gravity ii. Flash Point
iii. Volatility iii. Ash content
iv. Sulphur Content v. Corrosive property
vi. Heating value
Liquid fuels should have:
i. Low ash Content
ii. High heating value
iii.Less corrosive tendency
iv.Less Sulphur content
21. Gaseous Fuels
Natural Gas: The main components of natural gas are
Methane (CH4) and Ethane (C2H6). It has calorific value
nearly 21000 kJ/m3 .
Natural gas is used alternately of
simultaneously with oil for internal combustion.
Coal Gas: Hydrogen, Carbon monoxide, hydro-carbons.
Prepared by carbonization of coal. Used in boilers and for
commercial purpose.
Coke Oven Gas: It is obtained during the production of
coke by heating the bituminous coal
Blast Furnace gas: It is produced during smelting operation
in which air is forced through layers of coke and iron ore.
22. Advantages :
i. Cleanliness
ii. Better Control of combustion
iii.No problem of storage
iv.Much less excess air is required for complete
combustion
v. More efficiency of furnace operation
Composition of gaseous Fuels:
H2, CO, CH4, C2H4, C2H6, C4H8 , CO2 ,O2 , N2
23. Energy Stored in Water
• The energy stored in flowing streams of water contain
Mechanical Energy. It may exist as the kinetic energy
of a moving stream or as a potential energy of water
(dam).
Water power is quite cheap where water is available
in abundance.
Capital Cost of hydroelectric power plant is higher.
Operating cost is low.
24. Nuclear Energy
Nuclear power is cheaper as compared to other energy
sources.
i. 1 kg of Uranium = 4500 tones coal = 2000 tones of
oil
The capital cost is higher and there is safety factor
is also involved and problem of disposal of radio-
active material is also there.
25. Wind Energy
The expense of installation and variability of operation
have tend to limit the use of wind mills.
i. No fuel provision and transport are required
ii. Non polluting
iii. No maintenance is required over a long period
iv. Working life is about 20-25 years.
Disadvantages:
Noisy , Large area is required to build a wind form,
Irregular source
26. Solar Energy
• 1014
KW energy is being received by the surface of
earth, however this amount of energy is not easily
convertible.
• not constantly available
• Capital investment is high for the conversion
apparatus.
27. Tidal And Geothermal Energy
Rise and Fall of tides offer a mean for storing water
at the rise.
• water Head is very low
• Power generation is not continuous
• Favorable sites are limited
• Geothermal Energy
• 10,715 (MW) of geothermal power is online in 24
countries.
28. STEAM POWER PLANTS
• Using Coal, Gas or Oil or Nuclear Fission to generate
steam in boilers/steam generators.
• Steam is utilized to drive the turbines which are
coupled to generator to get electricity.
• This type of plant may contain several other heat
saving devices, like water heaters,
29. A thermal power station is a power plant
in which the prime mover is steam
driven. Water is heated, turns into steam
and spins a steam turbine which drives
an electrical Generator. After it passes
through the turbine, the steam is
condensed in a condenser and recycled
to where it was heated; this is known as
a Rankine cycle. The greatest variation
in the design of thermal power stations is
due to the different fuel sources.
Thermal Power Plant
31. The conversion from coal to electricity takes place in three stages.
Stage 1
The first conversion of energy takes place in the boiler. Coal is burnt in the
boiler furnace to produce heat. Carbon in the coal and Oxygen in the air
combine to produce Carbon Dioxide and heat.
Stage 2
The second stage is the thermodynamic process. The heat from combustion
of the coal boils water in the boiler to produce steam. In modern power
plant, boilers produce steam at a high pressure and temperature. The steam
is then piped to a turbine. The high pressure steam impinges and expands
across a number of sets of blades in the turbine. The impulse and the thrust
created rotates the turbine. The steam is then condensed to water and
pumped back into the boiler to repeat the cycle.
Stage 3
In the third stage, rotation of the turbine rotates the generator rotor to
produce electricity based of Faraday’s Principle of electromagnetic induction
33. 1. Cooling tower 2. Cooling water pump 3. Transmission line
4. Unit transformer (3-phase) 5. Electric generator (3-phase)
6. Low pressure turbine 7. Boiler feed pump 8. Condenser 9.
Intermediate pressure turbine 10. Steam governor valve 11.
High pressure turbine 12. Deaerator 13. Feed heater 14.
Coal conveyor hopper 15. Coal 16. Pulverized fuel mill 17.
Boiler drum 18. Ash hopper 19. Superheater 20. Forced
draught fan (3-phase) 21. Reheater 22. Air intake 23.
Economizer 24. Air preheater 25. Precipitator 26. Induced
draught fan 27. Chimney Stack
Components of a modern steam power plant
35. 1. Reliability 2. Minimum Capital Cost
3. Minimum operating and maintenance cost
4. Capacity to meet peak load effectively
5. Minimum losses of energy in transmission
6. Low cost of energy supplied to the consumer
7. Reserve capacity to meet future demand.
Essential Requirements of steam
power station design
36. Selection of site for Power Plant
1. Availability or raw material
2. Nature of land 3. Cost of land
4. Availability of water
5. Transport facilities 6. Ash disposal facilities
7. Availability of labour 8. Size of the plant
9. Load centre 10. Public problems
11. Future extensions etc.
