WHAT IS ENERGY?• ENERGY IS THE ABILITY OR THE CAPACITY TO DO • WORK.THERE ARE DIFFERENT FORMS OF ENERGY. • EACH FORM OF ENERGY CAN BE CONVERTED INTO • ANOTHER FORM.• IN OTHER WORDS WE CAN SAY THAT ENERGY IS CONSERVABLE.

• SOME EXAMPLES OF FORMS OF ENERGY ARE-POTENTIAL,THERMAL,ELECTRICAL,NUCLEAR,ETC.

WHAT IS A POWER PLANT?

A power plant is a source to harness energy.A power plant (also referred to as a generating

station, power station, or powerhouse) is an industrial facility for the generation of electrical energy.

At the centre of nearly all power plants is a generator, a rotating machine that converts mechanical energy into electrical energy by creating relative motion between a magnetic field and a conductor.

The energy source harnessed to turn the generator varies widely. It depends chiefly on which fuels are easily available and on the types of technology that the power company has access to.

HOW DOES A POWER PLANT WORK?

The heart of a power station is a large generator that extracts energy from a fuel. Some power stations burn fossil fuels such as coal, oil, or gas. Nuclear power stations produce energy by splitting apart atoms of heavy materials such as uranium and plutonium. The heat produced is used to turn water into steam at high pressure. This steam turns a windmill-like device called a turbine connected to an electricity generator. Extracting heat from a fuel takes place over a number of stages and some energy is wasted at each stage.

TYPES OF POWER PLANT ON THE BASIS OF WORKING

BY FUEL Fossil fuelled power plants ,Nuclear power

plants ,Geothermal power plants ,Biomass fuelled power plants ,Integrated steel mills ,Waste heat from industrial processes ,solar thermal electric plants.

BY PRIME MOVER Steam turbine plants ,Gas turbine

plants ,Combined cycle plants ,Water treatment plant ,Waste gas from oil production.

NUCLEAR POWER PLANT

NUCLEAR POWER PLANT

A nuclear power plant (NPP) is a thermal power station in which the heat source is one or more nuclear reactors.

A nuclear reactor produces and controls the release of energy from splitting the atoms of certain elements. In a nuclear power reactor, the energy released is used as heat to make steam to generate electricity

. The energy released from continuous fission of the atoms of the fuel is harnessed as heat in either a gas or water, and is used to produce steam. The steam is used to drive the turbines which produce electricity

How is energy released from the atom?Atoms of uranium are among the largest and also the heaviest

known to occur on earth. Being heavy they are also unstable. The nucleus of a uranium atom can easily break up into two smaller pieces. This process is called fission. The two fragments so produced fly apart with tremendous speed. As they collide with other atoms in a lump of uranium they come to a stop. In the process they heat up the uranium lump. This is how energy is released from the atom and converted to heat. The energy produced in fission is described as atomic energy by some and nuclear energy by others. Besides uranium, the atoms of plutonium are also fissionable. But plutonium does not occur in nature.

It has been found that 2 or 3 free neutrons are also released as a uranium atom breaks up during fission. When one of these neutrons collides with another uranium nucleus that nucleus also breaks up. In this manner using one neutron from every fission, we can cause another fission. This is known as chain reaction and produces heat at a steady rate.

HOW ENERGY IS OBTAINED?

COMPENENTS OF A NUCLEAR REACTORThere are several components common to most types of reactors: Fuel. Uranium is the basic fuel. Usually pellets of uranium oxide (UO2) are arranged

in tubes to form fuel rods. The rods are arranged into fuel assemblies in the reactor core.*

Moderator. This is material in the core which slows down the neutrons released from fission so that they cause more fission. It is usually water, but may be heavy water or graphite.

Control rods. These are made with neutron-absorbing material such as cadmium, hafnium or boron, and are inserted or withdrawn from the core to control the rate of reaction, or to halt it.

Coolant. A liquid or gas circulating through the core so as to transfer the heat from it. . In light water reactors the water moderator functions also as primary coolant. Except in BWRs, there is secondary coolant circuit where the steam is made.

Pressure vessel or pressure tubes. Usually a robust steel vessel containing the reactor core and moderator/coolant, but it may be a series of tubes holding the fuel and conveying the coolant through the moderator.

Steam generator. (not in BWR) Part of the cooling system where the primary coolant bringing heat from the reactor is used to make steam for the turbine. Reactors may have up to four "loops", each with a steam generator.

Containment. The structure around the reactor core which is designed to protect it from outside intrusion and to protect those outside from the effects of radiation in case of any malfunction inside. It is typically a metre-thick concrete and steel structure.

THERE ARE SEVERAL TYPES OF REACTORS

Pressurised Water Reactor (PWR).Fuel-enriched UO2

Boiling Water Reactor (BWR).Fuel-enriched UO2

Pressurised Heavy Water Reactor 'CANDU' (PHWR).Fuel-natural UO2

Gas-cooled Reactor (AGR & Magnox).Fuel-natural U (metal),enriched UO2

CHEMICAL CONVERSION TO UF6

ENRICHMENT

PELLETIZING

ROD LOADING

BUNDLE ASSEMBLY

BUNDLE FINAL INSPECTION

PACKAGING & SHIPPING

SITE INSPECTION & CHANNELING

Uranium Ore (0.7%)Fuel Pellet (3.5%)

ENRICHMENT(% U-235)

APPLICATIONS OF NUCLEAR POWER PLANTITS BASIC APPLICATION IS IN GENERATING LARGE AMONT OF HEAT AND

OBTAINING ELECTRICAL ENERGY.The most common use for a nuclear power plant is to generate electricity

for civilian consumption.Nuclear reactors are also used on sea-going vessels, where they provide

both electricity and mechanical power for propulsion.

The process of creating fuel for and running nuclear power plants produces a number of useful by products, or can be tailored to do so. Enriching uranium for fission reactors, for example, creates an isotope commonly known as depleted uranium, which the American military uses in the manufacture of both armour and ammunition due to its extremely high density. Then there are breeder reactors, which produce new fissile material (usually plutonium) at a rate greater than that at which the reactor consumes them, thereby creating a second generation of fuel. This reactor design is useful for its high fuel economy.

APPLICATIONS

U.S. nuclear-powered aircraft carrier.Red-hot pellet of plutonium meant for an atomic battery.

For the generation of electricity

In India we have nuclear power plant at Kaiga(880 MW) ,Kalpakkam(410 MW) ,Kakrapar(44o MW) ,Rawatbhata(1180 MW) ,Tarapur(1400 MW) ,Narora(440 MW).Some nuclear power plants which are under construction are Kundankulam(2000 MW) ,Kaiga(220 MW) ,Kalpakkam(500 MW) ,Rawatbhata(1400 MW).Some of the nuclear power plants have been planned for future.

LOCATIONS IN WORLD AND INDIA

ADVANTAGES OF NUCLEAR POWER PLANTS

1. The amount of electricity produced in a nuclear power station is equivalent to that produced by a fossil fuelled power station.2. Nuclear power stations do not burn fossil fuels to produce electricity and consequently they do not produce damaging, polluting gases. 3. Many developed countries such as the USA and the UK no longer want to rely on oil and gas imported from the Middle East, a politically unstable part of the world.4. Countries such as France produce approximately 90 percent of their electricity from nuclear power and lead the world in nuclear power generating technology - proving that nuclear power is an economic alternative to fossil fuel power stations. 5. Nuclear reactors can be manufactured small enough to power ships and submarines. If this was extended beyond military vessels, the number of oil burning vessels would be reduced and consequently pollution

DISADVANTAGES OF NUCLEAR POWER PLANT 1. Nuclear power is a controversial method of producing electricity.

2. There have been serious accidents with a small number of nuclear power stations. The accident at Chernobyl (Ukraine) in 1986, led to 30 people being killed and over 100,000 people being evacuated. In the preceding years another 200,00 people were resettled away from the radioactive area. Radiation was even detected over a thousand miles away in the UK as a result of the Chernobyl accident. It has been suggested that over time 2500 people died as a result of the accident.

3. There are serious questions to be answered regarding the storage of radioactive waste produced through the use of nuclear power. Some of the waste remains radioactive (dangerous) for thousands of years and is currently stored in places such as deep caves and mines.4. Storing and monitoring the radioactive waste material for thousands of years has a high cost.5. Nuclear powered ships and submarines pose a danger to marine life and the environment. Old vessels can leak radiation if they are not maintained properly or if they are dismantled carelessly at the end of their working lives.

HYDRO ELECTRIC POWER PLANT

WHAT IS HYDRO POWER?

The objective of a hydropower scheme is to convert the

potential energy of a mass of water, flowing in a stream with a certain fall to the turbine (termed the "head"), into electric

energy at the lower end of the scheme, where the powerhouse

is located. The power output from the scheme is proportional

to the flow and to the head.

TYPES OF HYDRO POWER PLANTTYPES OF HYDRO POWER PLANT

1) Water wheels1) Water wheels

2) Hydro power plants2) Hydro power plants

3) Wave energy from oceans3) Wave energy from oceans

4) Tidal energy4) Tidal energy

Based on the Head of Water Available Based on the Head of Water Available

1) Low head hydroelectric power plants1) Low head hydroelectric power plants

2)Medium head hydroelectric power plants 2)Medium head hydroelectric power plants

3) High head hydroelectric power plants 3) High head hydroelectric power plants

LAYOUT

ELEMENTS OF HYDRO POWER

DAMS

The movement of water can be used to make electricity. Energy from

water is created by the force of water moving from a higher elevation

to a lower elevation through a large pipe (penstock). When the water

reaches the end of the pipe, it hits and spins a water wheel or turbine.

The turbine rotates the connected shaft, which then turns the

generator, making electricity.

A dam failure can have sever effects downstream of the dam.

During the lifetime of a dam different flow conditions will be experienced

and a dam must be able to safely accommodate high floods that

can exceed normal flow conditions in the river. For this reason,

carefully passages are corporate in the dams as part of structure.

These passages are known as spillways.

What are Spill ways?What are Spill ways?

INTAKE

A water intake must be able to divert the required amount of

water in to a power canal or into a penstock without producing

a negative impact on the local environment.

INTAKE:-INTAKE:-

PENSTOCKPENSTOCK

PENSTOCK

“conveying water from the intake to the power house”.

The water in the reservoir is considered stored energy

When the gate opens the water flowing through the

penstock becomes kinetic energy because it is in motion.

SURGE TANK

• Surge tank is introduced in between the power house and dam to avoid sudden rise in the penstock.

• As the load is reduced then there will be a backflow of water inside the penstock.

• The back flow of water is known as water hammer.

TURBINES

• Kaplan• Francis• Pelton

2 < H < 4010 < H < 35050 < H < 1300(H = head in m)

The water strikes and turns the large blades of a turbine, which is attached to a generator above it by way of a shaft. The most common type of turbine for hydropower plants is the Francis Turbine, which looks like a big disc with curved blades.

After passing through the turbine the water returns to the

river trough a short canal called a tailrace.

Tailraces:-Tailraces:-

GENERATORGENERATOR

As the turbine turns, the exciter sends an electrical current

to the rotor. The rotor is a series of large electromagnets

that spins inside a tightly-wound coil of copper wire, called

the stator. The magnetic field between the coil and the

magnets creates an electric current.

TRANSFORMERS

A transformer is a device that transfers electrical energy from one circuit to another through a shared magnetic

field. A changing current IP in the first circuit (the primary) creates a changing magnetic field; in turn, this magnetic

field induces a voltage VS in the second circuit (the secondary). The secondary circuit mimics the primary

circuit, but it need not carry the same current and voltage as the primary circuit. Instead, an ideal transformer keeps the product of the current and the voltage the same in the

primary and secondary circuits.

OUTFLOW:-

Used water is carried through pipelines, called tailraces, and re-

enters the river downstream.

POWER HOUSE:-POWER HOUSE:-

ADVANTAGES & DISADVANTAGES OF HYDRO POWER PLANT

AdvantagesAdvantages

1) No fuel required 2) Cost of electricity is constant 3) No air-pollution is created 4) Long life 5) Cost of generation of electricity

6) Can easily work during high peak daily loads 7) Irrigation of farms 8) Water sports and gardens 9) Prevents floods

DISADVANTAGES1) Disrupts the aquatic ecosystems 2) Disruption in the surrounding areas 3) Requires large areas 4) Large scale human displacement 5) Very high capital cost or investment

6) High quality construction

7) Site specific 8) Effects on environment

9) Safety of the dams