Power Generation and Boiler Classification

Power Sector Growth

• India's power generation capacity grew from 1,362 MWe in 1947 to 1,43,542 MWe by November 30, 2008.
• Coal accounts for 55% of India's power generation
• The projected total capacity by 2012 is 215,800 MWe.

Boiler Classification

• Boilers are classified as either package or field erected.
• Types of boiler include fire tube and water tube.
• Boilers are also classified by their purpose: power boilers and utility boilers.

Fire Tube Boilers

• Combustion gases in a fire tube boiler pass through tubes submerged in water.
• The furnace in a fire tube boiler can be either separate or built into the boiler shell.
• Fire Tube boilers can be:
  • Dry back or Wet back
  • Oil fired or coal fired
  • Externally fired or internally fired
  • Through tube or Return tube
  • Horizontal, Vertical, or Inclined.
• Other designs include:
  • Simple Vertical Boiler
  • Two Pass Boiler
  • Scotch Marine Boiler
  • Locomotives type Boilers.

Water Tube Boilers

• Boilers are divided into Natural Circulation, Forced Circulation, and Assisted Circulation Types.
• Water tube boilers can be classified by the number of drums:
  • Drumless (Once Through Type)
  • Single Drum
  • Two (Bi-) Drum
  • Three (Tri-) Drum
  • Multi-Drum

Fuels Used in Boilers

• Solid Fuels:
  • Coal (Most Common)
  • Bagasse, Straw, Firewood, Other Bio-fuels
  • Coke breeze
  • Pet-coke
  • Washery Rejects/Middling
  • Municipal Garbage/Manure
• Liquid Fuels:
  • Fuel Oil: L.D.O./H.F.O./L.S.H.S./H.S.D.
  • Black Liquor (Pulp Industry Waste)
  • Naphtha
• Gaseous Fuels
  • Coke-oven Gas
  • Blast Furnace Gas
  • Corex Gas
  • Bio-Gas
  • Natural Gas

Solid Fuel Firing Systems

• For Coal Firing:

  • Fuel Bed Firing:
    • Chain Grate/Renfrew & Oldbury Stoker
    • Traveling Grate Stoker (Style 28X Stoker, Rotograte Spreader Stoker)
  • Suspension Firing:
    • Fluidizing Bed Firing:
      • Bubbling Fluidizing Bed Firing
      • Atmospheric Fluidizing Bed Firing
      • Circulating Fluidizing Bed Firing
      • Pressurized Fluidizing Bed Firing
    • Pulverized Coal Firing:
      • Direct Firing:
        • Front Fired
        • Opposed Fired
        • Downshot Fired (U-Type / W- Type )
        • Corner Fired
      • Indirect Firing:
        • Bin System
        • Burners: Laminar / Turbulent / Low-NOx

• For Bagasse Firing

  • Horse Shoe Furnace
  • Dumping Grate Furnace
  • Rotograte Furnace.

Liquid Fuel Firing Arrangement

• For Oil Firing:
  • Steam Atomized
  • Air Atomized
  • Pressure Atomized
• For Black Liquor
  • Black Liquor Guns Spraying on the Furnace Walls
  • Burning of Char at the Furnace Hearth.

Gaseous Fuel Firing Equipment

• For High C.V. Gases:
  • Spud Burners
• For Low C.V. Gases (such as Blast Furnace Gas):
  • Scroll Type Burners

Function of Steam Generators

• Generate steam at a specific rate, quantity, temperature, pressure, and superheat.
• Separates, washes, and dries the steam.
• Controls combustion or balances the rate of heat generation and absorption.
• Minimizes heat losses through incombustibles or ash.

Explore the significant growth of India's power sector and learn about various types of boilers used in the industry. This quiz covers the evolution of power generation capacity and details the classification of fire tube and water tube boilers. Test your knowledge on boiler designs and their applications in power generation.