Question

Calculate the gross and net calorific value of a coal sample from the following data obtained from a bomb calorimeter. Weight of coal 0.73 gm, weight of water in the calorimeter 1500 gm, water equivalent of calorimeter 470 gm, initial temp 25 C, and final temp, 28 C, percentage of hydrogen in coal 2.5%, latent heat of steam 587 cal/gm.

Answer 1

Gross Calorific value of the fuel is

= (470*4.184*(28-25))/0.73

(here 4.184 is the calorific value of water)

= 8081. 4 kj/kg

Net Calorific Value = Gross Calorific value - 24.44*9*%H

=8081.4 - 550

=7531 kj/kg