Calorific value of fuel

Calorific value of fuel -: The combustion of fuel is accompanied by a large amount of evolution of heat. In kcal , the number of heat units evolved by the complete combustion of fuel is called the calorific value of fuel .

         

Calorific value can be determined by boy's gas calorimeter or by bomb calorimeter.

Calorific value of fuel measured in two types- 

1. Higher calorific value ( H.C.V.)

2. Lower calorific value  (L.C.V.)

1. Higher calorific value -: The amount of heat liberated by tge unit quantity of fuel i.e., 1 kg , when the products of combustion are cooled to 15° C is called higher calorific value or gross calorific value of fuel. 

2. Lower calorific value -: It is defined as ,when heat taken away by the water due to surface moisture and combustion is subtract from higher calorific value is called lower calorific value. 

 L.C.V. = H.C.V. - Heat taken by water due to surface moisture and combustion 

L.C.V. = H.C.V. - Weight of water × Latent heat