A steam power plant consists of a boiler, steam turbine and generator, and other auxiliaries. The boiler generates steam at high pressure and high temperature. The steam turbine converts the heat energy of steam into mechanical energy. The generator then converts the mechanical energy into electric power. You can check this link for getting your next presentation designer:
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2. CONTENTS
Introduction
Layout of steam power plant
Different types of fuels used in steam power plant
Different types of stokers
Corrosion
Reference
3. INTRODUCTION
A steam power plant converts the chemical energy of the fossil fuel (Coal) into
mechanical energy/electrical energy.
This is done by raising the steam in the boilers, expanding it through the turbines and
coupling the turbines to the generators which converts mechanical energy to electrical
energy.
Purposes of Steam Power Plant
1. To produce electric power
2. To produce steam for industrial processes like textile, food manufacturers, paper mills
etc.
4. LAYOUT OF STEAM POWER PLANT
The Layout consists of four important systems.
Coal and ash handling system.
Air and flue gas system.
Feed water and steam generation system.
Cooling water system.
5. COMPONENTS OF STEAM POWER PLANT
1.Boiler
❖ Superheater
❖ Reheater
❖ Economizer
❖ Air-heater
2.Steam Turbine
3. Generator
4. Condenser
5. Cooling Tower
6. Circulating Water Pump
7. Boiler feed pump
8. Wagon Tippler
9. Crusher house
10. Coal Mill
11. Induced draught fan
12. Ash Precipitators
13. Boiler Chimney
14. Forced draught fan
15. Water treatment plant
16. Control room
17. Switch yard
7. DESCRIPTION OF COMPONENT
• Coal and ash handling system:
Coal arrives at the storage yard and after necessary handling passes to the furnace through
fuel feeding device. Ash after combustion collects at the back of the boiler and is removed to
the ash storage yard.
• Air and flue gas system:
Air is taken in from the atmosphere through the action of a forced or induced draught fan and
passes on to the furnace through the air preheater, where it has been preheated by the flue
gases which pass to the chimney via preheater.
• Feed water and steam generation system:
Condensate leaving the condenser is first heated in a closed feed water heater through
extracted steam from the lowest pressure extraction point of turbine. ----deaerator----
economiser -----boiler. In Boiler the water circulates due to difference in density of water in the
lower temp. and higher temperatures of boiler Wet steam from boiler is heated up in Super
heater----Prime mover---HP turbine---Super heater----LP turbine-----condenser ---hot well.
8. CONTI..
•Cooling water circuit:
The cooling water supply to the condenser helps in maintaining a low pressure in it. Water
may be taken from a natural source.
• Turbine
A steam turbine is a device that extracts thermal energy from pressurized steam and uses it
to do mechanical work on a rotating output shaft.
• Chimney
The chimney is used in all power plants only to discharge the flue gases high in the
atmosphere to maintain the cleanliness of the surrounding atmospheric air.
9. HOW COAL POWER PLANTS PRODUCE ELECTRICITY
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.
10. DIFFERENT TYPES OF FUEL USED IN STEAM POWER
PLANT
Fuel
Based on occurrence Based on state
Primary Fuel
(Natural)
Secondary Fuel
(Artificial)
Liquid FuelSolid Fuel Gaseous Fuel
11. FUEL USED FOR STEAM POWER GENERATION
• The primary fuels which are burned to release heat and generate steam in boilers are the
fossil fuels - coal, fuel oil and natural gas.
•In India, coal is the main source of energy because of its large deposits and availability.
• According to geological order of formation, coal may be of the following types with
increasing carbon content. Peat, Lignite, Sub-bituminous, Bituminous, Sub-anthracite,
Anthracite ,Graphite.
• Each type of coal has a certain set of physical parameters which are mostly controlled by
moisture, volatile content (in terms of aliphatic or aromatic hydrocarbons) and carbon
content.
• Peat contains up to 90% moisture and is not attractive as a utility fuel. Coal ‘Ranking’ is a
measure of carbon content in the coal. Lignite is considered to be low rank and anthracite to
be high rank.
12. DIFFERENT TYPES OF STROKE
Stoker is a power operated fuel feeding mechanism. The working of different types of
stokers is based on two principles, over feed and under feed types.
Overfeed Underfeed
Conveyor Stoker Spreader Stoker
Chain grate
Stoker
Single retort
Stoker
Multi retort
Stoker
Multi retort
Stoker
Stokers
14. General Attack
• When the corrosion is uniformly distributed
over the metal surface.
• The conceder amount of iron oxide produced
by generalized attack contribute to fouling
problem
• It is recognized by a roughening of the surface
and usually by the presence of corrosion
products
• The mechanism of the attack typically is an
electrochemical process that takes place at the
surface of the material
CORROSION ATTACK
15. Galvanic attack
• Galvanic corrosion occurs when two dissimilar metals come
in contact with each other. This corrosion is caused by the
potential difference that develops between the metals.
Galvanic corrosion occurs when the contact between
dissimilar metals is bare metal to bare metal and they are in
the same physical environment.
• A common area of galvanic corrosion is in cooling systems
that contain both steel and copper alloys. As the copper
components corrode, copper is released into the water. This
dissolved copper plates out on the steel surfaces and induces
galvanic corrosion on the steel.
• This is an area of concern in power plants, which use copper
alloys in the condenser or the feed water system. Corrosion
of copper alloys in the feed water components will plate out
on the inside of the steel water wall tubes; eventually
leading to water wall tube failures.
Common example in water system are
• Steel & brass , Zinc & brass , Aluminum & steel , Zinc &
steel ,
• If galvanic attack occurs the metal named first will corrode
CORROSION ATTACK
16. REFERENCE
• A steam power plant converts the chemical energy of the fossil fuel (Coal) into mechanical
energy/electrical energy. • This is done by raising the steam in the boilers, expanding it through
the turbines and coupling the turbines to the generators which converts mechanical energy to
electrical energy. • Purposes of Steam Power Plant 1. To produce electric power 2. To produce
steam for industrial processes like textile, food manufacturers, paper mills etc. 04-04-20173
• The Layout consists of four important systems. 1. Coal and ash handling system. 2. Air and flue
gas system. 3. Feed water and steam generation system. 4. Cooling water system. 04-04-20174
• Components of steam power plant 1.Boiler 7. Boiler feed pump * Superheater 8. Wagon Tippler *
Reheater 9. Crusher house * Economiser 10. Coal Mill * Air-heater 11. Induced draught fan
2.Steam Turbine 12. Ash Precipitators 3. Generator 13. Boiler Chimney 4. Condenser 14. Forced
draught fan 5. Cooling Tower 15. Water treatment plant 6. Circulating Water Pump 16. Control
room 17. Switch yard 04-04-20175
• Figure 1: General layout of steam power plant 04-04-20173
• Coal and ash handling system: Coal arrives at the storage yard and after necessary handling
passes to the furnace through fuel feeding device. Ash after combustion collects at the back of
the boiler and is removed to the ash storage yard. • Air and flue gas system: Air is taken in from
the atmosphere through the action of a forced or induced draught fan and passes on to the
furnace through the air preheater, where it has been preheated by the flue gases which pass to
the chimney via preheater. • Feed water and steam generation system: Condensate leaving
the condenser is first heated in a closed feed water heater through extracted steam from the
lowest pressure extraction point of turbine. ----deaerator----economiser -----boiler. 04-04-20177