A steam power plant generates mechanical energy from steam. It contains a furnace to burn fuel and produce steam, a steam generator or boiler, and a main power unit like a turbine or engine to convert the steam's heat energy into work. Key components include the boiler, prime mover, condensers, coal handling system, and pumps. Steam is generated in the boiler and drives the turbine or engine. Condensed steam is returned to the boiler through feedwater pumps to repeat the process. Proper fuel handling and combustion are required to efficiently produce high pressure steam for power generation.

1. TOPIC 3 STEAM
POWER PLANT
BY URAIA R MOCELEKA

2. INTRODUCTION
• Steam is an important medium of producing mechanical energy.
• Steam has an advantage that, it can be raised from water which is available in
abundance.
• Steam is used to drive steam engines. Steam turbines etc.
• Steam power station is most suitable where coal is available in abundance.

3. ESSENTIAL OF STEAM POWER PLANT EQUIPMENT
• A furnace to burn fuel
• Steam generator or boiler containing
water
• Main power unit such as engine or
turbine to use the heat energy of
steam and perform work.
• Piping system to convey steam and
water.

4. FOUR MAIN CIRCUITS IN THERMAL POWER PLANT
• Feed water and steam flow circuit
• Coal and ash circuit
• Air and gas circuit
• Cooling water circuit

5. TYPES OF SYSTEM AND COMPONENTS USED IN
STEAM POWER PLANT
• High pressure boiler
• Prime mover
• Condensers and cooling towers
• Coal handling system
• Draught system
• Pumping system
• Air preheater, economizer,
superheater. Feed heaters
• Feed water purification plant
• Air and dust handling system

6. STEAM CONDENSING SYSTEM
• Condensor
• Cooling tower
• Hot well
• Condenser cooling water pump
• Condensate air extraction pump
• Air extraction pump
• Boiler feed pump
• Make-up water pump

7. POWER STATION DESIGNS
• Selection of site
• Estimation of capacity of power
station
• Selection of turbine and their
auxiliaries
• Selection of boilers and auxiliaries
• Design of fuel handling systems
• Selection of condensers
• Design of cooling system and design
of piping system to carry steam and
water
• Selection of electrical generator
• Design of control of instruments
• Design of layout of power station

8. CHARACTERISTICS OF STEAM POWER PLANT
• Higher efficiency
• Lower cost
• Ability to burn coal especially oh high ash content and inferior coals.
• Reduced environmental impact in terms of air pollution.
• Reduced water requirement
• Higher reliability and availability

9. FUEL HANDLING
• Fuel delivery
• Outdoor storage
• In plant handling
• preparation
• Feeding the coal into furnace
• Unloading
• Covered storage
• Weighing and measuring

10. DEWATERING OF COAL
• Improved heating value
• Easier crushing and pulverizing.
• improved boiler performance
• Less ash to handle
• Easier handling
• Reduced transporting cost

11. FUEL BURNING
FURNACES

12. FIRING FUEL FURNACES CATEGORIES
• Grated fire furnaces
• Chamber fired furnaces
Used to burn solid fuels, may have
stationary or movable bed of fuel
• Hand fired
• Semi mechanized
Designed with stationary fire grates
• Stockers fired.
Furnace with travelling grates or
stokers

13. CHAMBER FIRED FURNACES
• Type of fuel to be burnt
• Type of firing to be used
• Amount of heat to be recovered
• Amount of steam to be produced
and its condition
• Pressure and temperature desired
• Grate area required
• Ash fusion temperature
• Flame length
• Amount of excess air to be used

14. CONDITION TO COMPLETELY BURN FUELS
• Temperature of flame in the furnace
to be high enough
• Fuel and air to be thoroughly mixed
• Equipment should be capable to
regulate the rate of fuel feed
• Fuel should be in the furnace for a
sufficient time
• Fuel and air supply must be
regulated to achieve optimum air
fuel ratio
• Coal firing equipment should have
means to hold and discharge the ash.

15. METHOD OF FIRING
• Hand firing
Simple method of firing coal into the
furnace.
Used for smaller plants
Limited to the size of the furnace
• Mechanical firing
Commonly used to feed solid fuels into
the furnace in medium and large size
power plants.

16. AUTOMATIC BOILER CONTROL
By means of automatic combustion
control it becomes east to maintain a
constant steam pressure and uniform
furnace draught and supply of air or
fuel can be regulated to meet changes
in steam demand.

17. PULVERIZED COAL
• This allows for the increase in its
surface exposure thus permitting
rapid combustion.
• Types
 ball mill
Hammer mill
Ball and race mill
 bowl mill
• Function
Drying
Grinding
Separation of particles of the desired
size.

18. PULVERIZED COAL FIRING
• Unit system or direct system
Hot air is passed through coal in the
feeder to dry the coal.
Coal is transferred to the mill where it
is pulverized.
Air is supplied to the mill by fan.
Air and coal is mixed and fired into the
burner.

19. PULVERIZED COAL BURNERS
• Mix coal and air thoroughly
• Deliver coal and air to the furnace in
right proportions and should
maintain a stable ignition.
• Coal air mixture should move away
from the burner at a rate equal to
flame front travel in order to avoid
flash back into the burner.

20. ASH DISPOSAL
• Ash produced in about 10-20% of the
total coal burnt.
• Handling of ash is a problem because
ash coming of the furnace is hot,
dusty and irritating to handle.
• Quenching of ash
Quenching reduces the temperature
of the ash
Reduces corrosive action of ash
Disintegrate clinkers
Reduces dust accompanying the ash

21. ASH HANDLING EQUIPMENT
• Functions
Should be able handle large
quantities of ash
Corrosion and wear resistant
Should remove from the furnace
Capital investment, operating and
maintenance cost must be low

22. COMMONLY USED ASH HANDLING SYSTEMS
• Hydraulic
• Pneumatic
• Mechanical
• Discharge equipment
Rail road cars
Motor truck
Barge