GENERATION CONVENTIONAL SOURCES STRUCTURE OF POWER SYSTEM Power system owned by state electricity boards. Private sector utilities operate in Mumbai, Kolkata, Ahmedabad Regional electricity boards – Northern, Southern, Eastern, Western, North-eastern. Power Grid corporation- Central. Introduction India is one of the world’s largest consumer of energy Installed capacity – 1,67,317 MW Thermal = 1,08,602 MW Nuclear = 4,780 MW Hydro = 37,367 MW
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GENERATIONCONVENTIONAL SOURCES
STRUCTURE OF POWER SYSTEM
Power system owned by state electricity boards.
Private sector utilities operate in Mumbai, Kolkata, Ahmedabad
Fuel stored and fed to the boiler through conveyor belts. Broken down into proper shape for complete burning.
Ash thus generated after burning is removed from the boiler through ash handling equipment
Air And Gas Circuit
Air is required for combustion of fuel and is supplied through fans
Air is passed through air preheater to extract energy from flue gases for proper burning of the fuel
Flue gases have ash and several gases which are passed through the precipitator(dust collector) and go to atmosphere through chimney.
Feed Water And Steam Circuit
Steam Converted to water by condenser.
Water is demineralized & hence not wasted to have better economic operation of the plant.
Some part of steam and water is lost while passing through different parts.
Boiler feed pump feeds water into the boiler drum where it is heated to form steam.
Wet steam is again heated in super heater before passing through the turbine
Steam is expanded in the turbine to run it. After which again it goes to boiler for reheating
Cooling Water Circuit
To condensate the steam, large quantity of cooling water is required which is taken from river or pondage
After passing through the condenser, it is fed back to the river or Pondage
Boiler
Turbine
Economizer
Selection Of site
Availability of cheap land.
Availability of water.
Availability of fuel.
Possibility of future expansion of the plant.
Away from the urban areas due to pollution.
The initial cost of plant.
Magnitude and nature of load to be handled.
Hydro Power Plant
India is Pioneer in HEP
Darjeeling(1898) and Shivanasamudra (1902) one of the first in Asia.
Installed Capacity – 37,367MW
Advantages of Hydro Power Plant
Water is self – replenishing, non wasting.
Water reaches the powerhouse site on its own.
Water after producing electricity can be used for drinking or irrigation.
Efficiency of HEP is high(about 80%).
HEP has very long life.
Maintenance is easy and less expensive.
The percentage outage is low.
Benefits of recreation, fisheries etc.
Selection of sites
Availability of water
Storage of water
Head of water
Distance of power station to the load centres
Accessibility of site
Classification of HEP based on Capacity
Very low-capacity plants – up to 0.1MW
Low capacity plants – up to 1.0 MW
Medium-capacity plants – up to 10 MW
High-capacity plants – more than 10 MW
Classification of HEP based on Capacity
Micro Hydro plants : < 100KW
Mini Hydro plants : 100KW to 1MW
Small Hydro plants : 1MW to few MW
Hydro plants : More than a few MW
Super Hydro plants : More than 1000MW
Classification of HEP based on Head
Low-head Plants < 15m
Medium-head Plants 15 – 70m
High-head Plants 71 – 250m
Very High-head Plants > 250m
Nuclear Power Plants
Twenty Nuclear Reactors
Production – 4780 MW
Energy from atomic nuclei via controlled nuclear reactions(Fission)
Uranium-235 and plutonium-239.
Nuclear Fission
NPP Using A Heat Exchanger
PWR – Pressurized Water Reactor(Nuclear Furnace or Pile)
Main Components Of A Reactor
Fuel Rods – Tube filled with pellets of Uranium
Shielding - Protection against alpha, beta and Gamma Rays
Moderator - Slow down the neutron release(Heavy water, Beryllium, Graphite)
Control Rods - neutron absorbing material(boron Carbide, cadmium)
Coolant - To transfer the heat generated inside the reactor to a heat exchanger for utilization of power generation(CO2, H2, He, heavy water, liquid metal-Sodium or Potassium)
Steam Separator - steam from the heated coolant is fed to the turbines to produce electricity from generator.
Containment - concrete lined cavity acting as a radiation shield
Boiling Water Reactor (BWR)
Heavy Water Reactor(CANDU)
Gas-Cooled Reactor
Selection of Site
Availability of water - NPP requires ample amount of water for cooling and steam generation.
Disposal of Waste – Dangerous waste/residue obtained
It needs to be disposed deep under the ground in sea so that radioactive effect is eliminated.
Away from populated area – For health safety
Nearest to the load centre
Other Factors – Accessibility to the road and rail are general considerations.
Advantages of NPP
Fuel is easy to transport.
Energy generated is very efficient and the remaining waste is compact.
Nuclear reactors need little fuel.
Amount of waste produced is much smaller than that produced in coal burning plant
Chance of a nuclear accident is 1 in 250 years.
Clean source of energy.
Disadvantages
Actual cost of producing energy is more because of containment, radioactive waste storage system
The mining of the fuel itself can cause serious problems
The meltdown of reactor can cause serious disaster.
GAS POWER PLANT
Axial Compressor
Air is taken from the atmosphere , compressed, heated (usually by combustion of fuel in the air) and expanded in the turbine.
Gases coming out of the turbine are exhausted in the air.
Used in emergency and when there is peak demand.
Fossil fuels such as gasoline, natural gas etc are used as fuel
Diesel Engine
It is an internal combustion engine that uses the heat of compression to initiate ignition to burn the fuel, which is injected into the combustion chamber.
Diesel engines are manufactured in two stroke and four stroke versions.
Used to drive the prime mover of electric generators
Used as a stand-by set for start up of auxiliaries in steam and gas power plants
Used for emergency supply to hospitals, hotels, factories and in other commercial units.
