A boiler produces 9 kg steam/kg of coal burnt, which has a calorific value of 27 MJ/kg. The enthalpy of feed water and steam at the exit are 300 kJ/kg and 3000 kJ/kg respectively. Its thermal efficiency is:

A boiler produces 9 kg steam/kg of coal burnt, which has a calorific v

1.	A boiler produces 9 kg steam/kg of coal burnt, which has a calorific value of 27 MJ/kg. The enthalpy of feed water and steam at the exit are 300 kJ/kg and 3000 kJ/kg respectively. Its thermal efficiency is:
A.	90%
B.	83.57%
C.	55%
D.	94.2%
Answer» B. 83.57%