The calorific value of a fuel is the quantity of heat produced by its combustion – at constant pressure and under “normal” (standard) conditions (i.e. to 0oC and under a pressure of 1,013 mbar).
The combustion process generates water vapor and certain techniques may be used to recover the quantity of heat contained in this water vapor by condensing it.
- Higher Calorific Value (or Gross Calorific Value – GCV, or Higher Heating Value – HHV) – the water of combustion is entirely condensed and that the heat contained in the water vapor is recovered;
- Lower Calorific Value (or Net Calorific Value – NCV, or Lower Heating Value – LHV) – the products of combustion contains the water vapor and that the heat in the water vapor is not recovered.
Fuel Calorific Values
|Natural gas||12500 kcal/kg|
|Fuel oil||9520 kcal/kg|
|Brown coal||3500 kcal/kg|
1 kW is obtained from:
|0.072 kg||natural gas|
|0,092 kg||fuel oil|
|0,218 kg||brown coal|
Composition of Natural Gas
|Propane C3H8||Butane C4H10 Carbon Dioxide CO2 0-8%|
|Hydrogen sulphide H2||S 0-5%|
|Rare gasesA, He, Ne, Xe||trace|