FUELS AND COMBUSTION – MODULE 6
FUELS
A combustible substance, upon burning in air/O2 gives large amount of heat. Eg:
wood, charcoal, petrol, LPG etc.
COMBUSTION
A process in which a substance burn in air/O2 with evolution of heat.
Thus, energy released during the combustion process is the difference in the
energy of the reactant and that of products formed.
CLASSIFICATION OF FUELS
,DEFINITION OF 1 CALORIE
UNITS OF HEAT
CALORIFIC VALUE AND ITS UNITS
Unit of Calorific Value for Solid and Liquid Fuels
• Calories/gram (cal/g)
• Kilocalories/Kilogram (Kcal/Kg)
Unit of Calorific Value for Gaseous Fuels
• Cal/cm3 at given Temperature and Pressure
• Kcal/m3 at given Temperature and Pressure
(Since Volume of a gas varies with Temperature and Pressure, Calorific Value of
gases include Temperature and Pressure)
, TYPES OF CALORIFIC VALUE OF A FUEL
(1) Gross/Higher calorific value (GCV/HCV)
(2) Net/Lower calorific value (NCV/LCV)
CHARACTERISTICS OF A GOOD FUEL
FUELS
A combustible substance, upon burning in air/O2 gives large amount of heat. Eg:
wood, charcoal, petrol, LPG etc.
COMBUSTION
A process in which a substance burn in air/O2 with evolution of heat.
Thus, energy released during the combustion process is the difference in the
energy of the reactant and that of products formed.
CLASSIFICATION OF FUELS
,DEFINITION OF 1 CALORIE
UNITS OF HEAT
CALORIFIC VALUE AND ITS UNITS
Unit of Calorific Value for Solid and Liquid Fuels
• Calories/gram (cal/g)
• Kilocalories/Kilogram (Kcal/Kg)
Unit of Calorific Value for Gaseous Fuels
• Cal/cm3 at given Temperature and Pressure
• Kcal/m3 at given Temperature and Pressure
(Since Volume of a gas varies with Temperature and Pressure, Calorific Value of
gases include Temperature and Pressure)
, TYPES OF CALORIFIC VALUE OF A FUEL
(1) Gross/Higher calorific value (GCV/HCV)
(2) Net/Lower calorific value (NCV/LCV)
CHARACTERISTICS OF A GOOD FUEL
