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 RES = 16,787 MW Per capita power consumption – 612KWH Annual power production – 680 billion KWH
Break up of Power Thermal power Plants : 65.34%[ Hydro Electric Power Plants : 21.53% Nuclear Power Plants : 2.70% Renewable energy sources : 10.42% 30% to 40% of electrical power is lost in transmission and distributionThermal Power Plants Installed Capacity – 65% of total installed capacity. Coal based –54% of total installed capacity. Gas Based –10% of total installed capacity. Oil Based –1% of total installed capacity.Main Components Fuel Handling Unit Ash Handling Unit Boiler Unit Feed Water Unit Cooling Water Unit Generator Unit
Turbine UnitMain Circuit Fuel And Ash Circuit Air And Gas Circuit Feed Water And Steam Circuit Cooling Water CircuitFuel And Ash Circuit 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 equipmentAir 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 reheatingCooling 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
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. Advantages: High operating efficiency. Need very little water for cooling. Quick start and stop is possible. Easier handling of fuel.