Important Points of Thermal Power Plants Coal, Gas/Diesel and Nuclear Based

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Important Points of Thermal Power Plants Coal, Gas/Diesel and Nuclear Based

Q. List of thermal power stations in India.
Q. List of thermal power stations in Maharashtra.
Following points affect in selection of site for thermal power station :

  1. Cost of land
  2. Private land
  3. Availability of water
  4. Cost of fuel
  5. Possibility of good foundation
  6. Should be away from residential area
  7. Possibility of industrial growth
  8. Possibility of future expansion
  9. Facility for disposal of ash
  10. It should serve the interest of national defence.

Drawn schematic layout of a typical thermal power station
Types of fuels :

  1. Solid
  2. Liquid
  3. Gaseous

Analysis of coal

  1. Proximate analysis
  2. Ultimate analysis

Main components of thermal power station:

  1. Coal handling unit
  2. Boiler
  3. Economizer
  4. Air preheater
  5. Superheaters and reheaters
  6. Steam operated prime movers
  7. Condensers
  8. Spray ponds and cooling towers

Methods of dust collection in Thermal Power Plant :

  1. The setting chamber
  2. impingement separators
  3. Cyclone separators
  4. Fabric filters
  5. Electrostatic precipitators

Layout of typical thermal plant and study of :

  1. Water treatment plant
  2. Control room
  3. Switch yard

Factors to be considered to select site for nuclear power station :

  1. Proximity to load centre
  2. Availability of water
  3. Transportation facilities
  4. Radioactive waste disposal
  5. Distance from populated area

A neutron on colliding with an atom interacts with the nucleus and produces following effects :

  1. Elastic collision
  2. Inelastic collision
  3. Absorption
  4. Fission

Multiplication factor :
K =  Number of neutrons of any one generation / Number of neutrons of immediate preceding generation

  • Critical size : For the system to be critical the value of K = 1.
  • Fuels used in nuclear power plant are 

Main components of nuclear reactor :

  1. Fuel
  2. Moderator
  3. Control rods
  4. Shielding
  5. Heat exchanger
  6. Turbine
  7. Condenser
  8. Feed water heater
  9. Reflector
  10. Coolant
  11. Reflector vessel.

Types of nuclear reactors :

  1. Pressurised water reactor
  2. Boiling water reactors
  3. Gas cooled reactors
  4. Fast breeder reactor

Classification of radioactive waste :

  1. Low Level Waste (LLW)
  2. Intermediate Level Waste (ILW)
  3. High Level Waste (HLW)

For nuclear power plant, the cost is involved in :

  1. Fuel
  2. Capital
  3. Security and Uranium processing
  4. Waste disposal
  5. Decommissioning
  6. Insurance

Advantages of Nuclear Plant :

  1. Saving of natural resources such as coal, gas, oil etc.
  2. Less area is required
  3. Fuel required is small, as 1 kg of nuclear fuel equals to 2800 tonnes of coal.
  4. Independent of geographical conditions
  5. It can be located near load centre
  6. It is economical
  7. Operation is clean, no ash and no toxic fumes etc.

Disadvantages of Nuclear Plant :

  1. High capital cost
  2. Fuel is not readily available
  3. Construction is complicated
  4. Not suited for varying loads
  5. Danger of radiation is always present
  6. Disposal of waste is problematic
  7. High maintenance charges
  8. There is a danger of accident when transporting nuclear fuel or nuclear waste
  9. Enrichment technology is essential for fuel processing and fabrication

Following are main fields of application of diesel plants :

  1. Central stations
  2. Standby plant
  3. Peak-load plant
  4. Emergency plant
  5. Mobile plant
  6. Nursery stations

Following factors decide site for diesel stations :

  1. Distance from load centre
  2. Availability of land and water
  3. Foundations
  4. Transport of fuel
  5. Local conditions
  6. Neighbourhood noise and nuisance 

Following are main components of diesel electric plant :

  1. Engine fuel system
  2. Engine air intake system 
  3. Engine exhaust system
  4. Engine cooling system
  5. Engine lubrication system
  6. Engine starting system
  7. A.C. or D.C. generator

Following are main parts of engine : 

  1. Cylinder 
  2. Cylinder head
  3. Piston and piston rings 
  4. Connecting rod
  5. Crank shaft and webs 
  6. Main bearings
  7. Crank pin and bearing
  8. Nozzle
  9. Piston pin and bearing 
  10. Exhaust valve
  11. Camshaft
  12. Valve springs
  13. Cylinder block or crank case
  14. Fly wheel
  15. Bed plate 
  16. Cooling water jackets 

Dual fuel engines are those which make use of gas and oil both.
Diesel engines are of the following types :
    a) Four-stroke engine
    b) Two stroke engine 

Engines may have number of cylinders depending upon power requirement and termed as :

  1. One cylinder engine
  2. Two cylinder engine
  3. Four cylinder engine etc.

Advantages of diesel plant :

  1. It can be installed at load centre
  2. It can be started in short time and take load immediately
  3. Layout and construction is simple
  4. Space required is less
  5. Number of accessories required is less
  6. Water required for cooling is less
  7. Overall efficiency is high
  8. Number of skilled personnel required is less
  9. Number of spares required is less
  10. Overall cost per kW of installed capacity is less

Disadvantages of diesel plant :

  1. Fuel used cost is more
  2. Overload capacity is less
  3. Generating capacity is less
  4. Cost of lubricants is more

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