CALORIFIC VALUE OF FUEL

YOU TAKE I KG OF FUEL EITHER SOLID OR LIQUID
YOU REQUIRE TO BURN IT FULLY SO ALL HEAT IS LIBERATED FROM THE FUEL.
THE AMOUNT OF HEAT LIBERATED IS ITS CALORIFIC VALUE.
ITS UNIT WILL BE KJ/KG (KILO JOULE/KILOGRAM)

FOR GASEOUS FUELS IT CAN EXPRESSED AS KJ/CUBIC METER (KJ/ M^3) OF GAS AT (STP) STANDARD TEMPERATURE AND PRESSURE.


NOW UTILIZATION OF THE HEAT

HYDROGEN BURNS TO FORM STEAM. ALSO IF THE FUEL CONTAINS MOISTURE . THIS TAKE AWAY SOME HEAT FROM THE FUEL WHILE FORMING STEAM.
WHEN THIS STEAM IS CONDENSED AGAIN AT ITS INITIAL TEMPERATURE AT WHICH TEMPERATURE YOU STARTED TO BURN THE FUEL. WITH THIS PROCESS  TOTAL HEAT OF THE FUEL  CAN BE DETERMINED.
THIS  HEAT VALUE IS  HIGHER CALORIC VALUE OF THE FUEL.

IN PRACTICE HEAT CARRIED AWAY BY STEAM IS NOT UTILIZED , BUT YOU HAVE TO KNOW THE NET HEAT VALUE GENERATED BY THE FUEL.
THIS NET HEAT VALUE IS ITS LOWER CALORIFIC VALUE

HEAT TAKEN AWAY BY STEAM IS THE MASS OF STEAM AND THE LATENT HEAT OF STEAM FORMATION AT THAT CONDITION.

COMMON PRACTICE IS TO TAKE THE CONDITION AT 15 DEGREE CENTIGRADE

LATENT HEAT AT SATURATION TEMPERATURE OF STEAM IS 2466 KJ/KG.

IF P IS THE AMOUNT OF STEAM

SO

LCV= HCV-Px2466 KJ/KG.