POWER PLANT TECHNOLOGY
The engineering & technology involve in the
production or generation of electricity is called as
Power Plant Technology.
TYPES OF POWER PLANT
THERMAL POWER PLANT
HYDROELECTRIC POWER PLANT
NUCLEAR POWER PLANT
Thermal Power Plant Consist Of
Feed water heater
A boiler is an enclosed vessel that provides a
means for combustion heat to be transferred
into water until it becomes heated water or
Steam. The hot water or steam under pressure
is then usable for transferring the heat to a
Turbine, rotary engine that converts the energy of a moving
stream of water, steam, or gas into mechanical energy.
The basic element in a turbine is a wheel or rotor with
paddles, propellers, blades, or buckets arranged on its
circumference in such a fashion that the moving fluid
exerts a tangential force that turns the wheel and imparts
energy to it. This mechanical energy is then transferred
through a drive shaft to operate a machine, compressor,
electric generator, or propeller.
Turbines are classified as hydraulic,
turbines,steam turbines, or gas turbines.
A deaerator is a device that is widely used for the removal of air
and other dissolved gases from the feed water to steam
generating boilers. In particular, dissolved oxygen in boiler feed
waters will cause serious corrosion damage in steam systems by
attaching to the walls of metal piping and other metallic
equipment and forming oxides (rust).
4. Heat Exchangers :
Heat exchangers are equipment that transfers heat from
one medium to another.
The proper design, operation and maintenance of heat
exchangers will make the process energy efficient and
minimize energy losses.
Heat exchangers may be classified according to their flow
In parallel-flow heat exchangers, the two fluids enter the
exchanger at the same end, and travel in parallel to one
another to the other side.
In counterflow heat exchangers the fluids enter the
exchanger from opposite ends.
In a cross-flow heat exchanger, the fluids travel roughly
perpendicular to one another through the exchanger.
5. Super Heater:
A super heater is a device in a steam engine that
heats the steam generated by the boiler again,
increasing its thermal energy and decreasing the
likelihood that it will condense inside the engine.
Super heaters increase the efficiency of the steam
engine, and were widely adopted.
Steam which has been superheated is logically
known as superheated steam; non-superheated
steam is called saturated steam or wet steam.
•The surface condenser is a shell and tube heat exchanger in which
cooling water is circulated through the tubes.
•The exhaust steam from the low pressure turbine enters the shell
where it is cooled and converted to condensate (water) by flowing
over the tubes as shown in the adjacent diagram.
•Such condensers use steam ejectors or rotary motor-driven
exhausters for continuous removal of air and gases from the steam
side to maintain vacuum.
Economizers are mechanical devices intended to
reduce energy consumption, or to perform another
useful function like preheating a fluid.
8.Feed water heater:
The condensate pump pumps the condensate water
through a feed water heater.
The feed water heating equipment then raises the
temperature of the water by utilizing extraction steam from
various stages of the turbine. Preheating the feed water
reduces the irreversibilities involved in steam generation
and therefore improves the thermodynamic efficiency of the
9. Electrical generator:
In electricity generation, an electrical generator is a
device that converts mechanical energy to
electrical energy, generally using electromagnetic
ADVANTAGES OF THERMAL POWER PLANT:
Fuel used is cheaper.
Less space required in setup in comparison to
hydroelectric power plant.
They can be located conveniently near the load
A portion of steam generated can be used as a
process steam in different industries.
As these plants can be set up near industries,
therefore the transmission costs are reduced.
DISADVANTAGES OF THERMAL POWER PLANT:
Maintenance & operating costs are high.
Cost of plant increases with increase in
temperature & pressure.
Long time required for erection & putting into
Greatly difficulty experienced in cool handling.
Presence of troubles due to smoke & heat in the
Smoke & gaseous emission cause pollution in the
HYDROELECTRIC POWER PLANT
A hydroelectric power plant harnesses the energy
found in moving or still water and converts it into
HOW HYDROELECTRIC POWER PLANT
A dam is built to trap water, usually in a valley where there
is an existing lake. Water is allowed to flow through tunnels
into the dam, to turn turbines and thus drive generators.
Water from the reservoir flows due to gravity to drive the
turbine. Turbine is connected to a generator.
Power generated is transmitted over power lines.
A water turbine that convert the energy of flowing or falling
water into mechanical energy that drives a generator, which
generates electrical power. This is a heart of hydropower
COMPONENTS OF HYDROELECTRIC POWERPLANT
Dam and Reservoir
The rain water falls on a large area called catchment area,
gets collected in the form of streams and flows as runoff
to plant site.
The dam is usually built on a large river that has a drop in
elevation, so as to use the forces of gravity to aid in the
process of creating electricity. A dam is built to trap
water, usually in a valley where there is an existing lake.
An artificial storage reservoir is formed by constructing a
dam across a river.
The area behind the dam where water is stored is called the
reservoir. The water there has gravitational potential
energy. The water is in a stored position above the rest of
the dam facility so as to allow gravity to carry the water
down to the turbines.
It carries water from reservoir to the hydraulic turbine. The
penstock is a long shaft that carries the water towards the
turbines where the kinetic energy becomes mechanical
energy. The force of the water is used to turn the turbines
that turn the generator shaft
Trash rack, Gates and anchorages:
Trash rack prevent the entry of debris into the
penstock. These debris would otherwise damage
the gates, nozzles and turbine blades by erosion.
Gates control and regulate the flow of water into
Anchorages prevent the movement of penstock due
to dynamic forces at vertical and horizontal bends
and on slopes.
Draft tube is a kind of a diverging passage. Because of
this shape, the water flows through this tube is
deaccelerated and it comes out of tube with minimum
The exit of draft tube is submerged in tail race.
Control Gates & Spillway:
Control gates arrangement is provided with Spillways.
Spillway is constructed to act as a safety valve. It
discharge the overflow water to the down stream side
when the reservoir is full.
Draft tube and tail race:
It is a safety device.
SURGE TANK acts as a temporary reservoir. It helps in
stabilizing the velocity and pressure in penstock and
thereby saves penstock from getting damaged
ADVANTAGES OF HYDROELECTRIC POWER PLANT:
No fuel charges.
An HEP is highly reliable & has long life.
Maintenance & operation charges are very low.
Running cost of the plant is low.
No ash problem & atmosphere is not polluted
since no smoke is produced in the plant.
In addition to power generation these plants can
also be used for flood control & irrigation
These are set up away from the developed area
hence cost of land is not a major problem.
DISADVANTAGES OF HYDROELECTRIC POWER PLANT:
Initial cost of plant for set up is very high.
It takes considerably long time for the
erection of such plants.
Since such plants are usually located in hilly areas
& far away from the load centre, so they require
long transmission lines to deliver power
subsequently the cost of transmission lines &
losses in them will be more.
NUCLEAR POWER PLANT
The Nuclear power plant converts nuclear energy into
Nuclear power reactors or nuclear power plants create
electricity by combining chemical reactions and heat.
Nuclear fission: The fuel most widely used by nuclear
power plants for nuclear fission is uranium.
In nuclear fission, a small particle called a neutron hits the
uranium atom and it splits, releasing a great amount of
energy as heat and radiation. As more neutrons are released
they bombard other uranium atoms, and the process of
nuclear fission repeats itself over and over again. This is
called a chain reaction. Nuclear plants use the heat given
off during fission as fuel. Fission takes place inside the
reactor of a nuclear power plant
COMPONENTS OF NUCLEAR POWER PLANT:
A nuclear reactor is a device in which nuclear chain
initiated, controlled, and sustained at a
Advantages of nuclear power plant:
It avoids the wide variety of environmental
problems arising from burning fossil fuels - coal,
oil, and gas.
It is possible to generate a high amount of
electrical energy in one single plant using small
amount of fuel.
Nuclear power is reliable. This technology is
readily a available.
Produces small amounts of waste.
Nuclear power is also not so expensive as compare
to power from coal.
DISADVANTAGES OF NUCLEAR POWER PLANT:
The problem of radioactive waste is still an
High risks: It is technically impossible to build a
plant with 100% security.
The energy source for nuclear energy is Uranium.
Uranium is a scarce resource; its supply is
estimated to last only for the next 30 to 60 years
depending on the actual demand.