A brief explanation of how steam power plant works and what are the main factors effecting it. I also include figure and video which will help you better understand this process.

1. Steam Power Plant
Thermal Energy Converted into Electrical Power

2. Table of Contents
•Basics
•Arrangements
•Cooling
•Location
•Efficiency

3. Basic
Definition, Advantages & Disadvantages
• Steam power plant converts heat energy into electrical energy.
• The Rankine cycle is the fundamental operating cycle of all power
plants where an operating fluid is continuously evaporated and
condensed.
• We use different type of fuels such as Coal, Natural Gas etc.
• The typical life is 30 to 40 years.

4. Basic
Definition, Advantages & Disadvantages
• Rankine Cycle:
It is an idealized thermodynamic cycle
of a heat engine that converts heat into
mechanical work while undergoing phase
change. The heat is supplied externally to
a closed loop, which usually uses water as
the working fluid.

5. Basic
Definition, Advantages & Disadvantages
• Advantages
• Cheap coal is used
• Can be installed anywhere
near fuel & water supply
• Requires less construction
space
• Cost of generation is less
• Disadvantages
• Air pollution from smoke
fumes
• Costs more to run compared
with other types of power
station

6. Arrangements
Components that make up a steam power station
1. Cooling tower
2. Cooling water pump
3. Pylon (termination tower
4. Unit transformer
5. Generator
6. Low pressure turbine
7. Boiled feed pump
8. Condensor
9. Intermediate pressure
turbine
10.Steam governor
11.High pressure turbine
12.Deaerator
13.Feed heater
14.Coal conveyor
15.Coal hopper
16.Pulverised fuel mill
17.Boiler drum
18.Ash hopper
19.Super heater
20.Forced Draught fan
21.Reheater
22.Air Intake
23.Economiser
24.Air preheater
25.Precipitator
26.Induced draught fan
27.Chimmney stack

7. This schematic diagram must be properly understood. it is the basis
upon which Steam power station designs are done. the individual
power station complexity may differ slightly to the schematic and yet
over and above that will use the same principle.

8. Arrangements
Components that make up a steam power station
• Stage 1: Coal & Ash handling
This stage is seen as the entrance and exit of fuel (coal) used. The
initial handling treatment and storage of coal and the final handling
and disposal of Ash.
*Coal conveyor (14) *Coal hopper (15) *Pulverizer Mill (16)
*Ash hopper (18)

9. Arrangements
Components that make up a steam power station
• Stage 2: Steam Generating Plant
This stage is seen as the energy loss stage. The steam creation by
heat accounts for the greater percentage of power station in-
efficiency.
*Boiler drum (17) *Superheater (19) *Reheater (21)
*Economizer (23) *Preheater(24) *Forced d-fan(20)
*Induced d-fan(26) *Chimney(27)

10. Arrangements
Components that make up a steam power station
• Stage 3 & 4: Steam Turbine & Alternator/Generator
This stage is seen as the energy conversion stage. The steam turbine
converts steam energy to rotational mechanical energy, while the
Alternator/Generator converts rotational mechanical energy into electrical
energy.
*Pressure turbines (6; 9 & 11) *Steam governor (10) *Boiler feed pump (7)
*Generator (5) *Transformer (4) *Pylon (3)

11. Arrangements
Components that make up a steam power station
• Stage 5: Feed Water & Cooling
This stage is seen as the recycling stage. Steam used in boiler
chamber is condensed back to water for re-use.
*Cooling tower (1) *Water pump (2) *Condenser (8)
*Precipitator (25)

12. Cooling
Wet cooling method
The condenser itself uses cold water and employs the principle of
heat exchange. As the cool water is returned to the boiler, the hot
water in the condenser is pumped to the cooling tower. Here water
is sprayed and thus falls down to the water pond under the cooling
tower. As the water falls it is cooled by the natural cold air. The
cooled water is pumped back to the condenser, and the cycle is
repeated. This method uses a lot of water through evaporation.
Water Consumption
≈ 2.5 lt/kWh

13. Cooling
Dry cooling method
• In this method steam is circulated inside a radiator-like heat
exchanger and is cooled by the natural cold air blown
(naturally or using draught fans) between pipes of the heat
exchanger. The cooled/condensed steam is returned to the
boiler(Rankine cycyle).
• This method greatly decreases water wastages through
evaporation by almost 84% of the wet cooling method. It is
called Direct dry cooling since the condenser has been
eliminated completely. This method is favored where water
is scarce.
Water
Consumption
≈ 0.4 lt/kWh

14. Cooling
Wet cooled condenser
Here the condenser is still used to cool steam that is pumped back
to the boiler. The hot water from the condenser is then pumped to
Heat exchangers in the cooling tower and natural ventilation is used
to cool the water which can then be pumped back to the condenser.
Notice that water consumption here is double that consumed in the
direct dry cooling method.
Water Consumption
≈ 0.8 lt/kWh

15. Cooling
Jet cooled condenser
Here the exhaust steam leaving the low-pressure turbine condensed
by a jet spray of cold water. the resulting hot water collected is
through heat exchangers in the cooling tower. The cooled water is
sent back to the boiler. Notice that water consumption is equal to
the previous cooling method.
Water Consumption
≈ 0.8 lt/kWh

16. Location
Factors influencing selection of construction site.
1. Supply of fuel:
The station must be located close to coal mines to reduce
transportation cost of fuel.
2. Availability of water:
The station must be located near a river bank or canal for
continuous water supply.
3. Transportation facilities:
The station must be well connected to major transport routes
eg Rail or Road.

17. Location
Factors influencing selection of construction site.
4. Cost & type of land:
The land must have a good bearing capacity for heavy
equipment and yet be cheap enough to purchase.
5. Distance from populated areas:
The station must be located as far away from populated areas
as possible due to air pollution.
6. Nearness to load centers:
In order to reduce the transmission cost the plant should be
located near load centers.

18. Efficiency
How efficient this power station is.
This type of power station has very high energy losses due to great
heat loss in the boiler and condenser. the following equation is used
to calculate power station efficiency:
The above generally works out to ±30% for steam power stations.

19. Efficiency
How efficient this power station is.
We can further calculate overall efficiency as follows:
The above generally works out to ±29% ( 1% loss at the generator )
for steam power stations.

20. Thank you
Any Question?

21. References
• V.K Mehta & Rohit Mehta :- Principles of Power systems (1st ed.).
S.CHAND
• https://en.wikipedia.org/wiki/Thermal_power_station