The difference between GCV and NCV

 The difference between Gross Calorific Value (GCV) and Net Calorific Value (NCV) lies in how they account for the heat of vaporization of water in the combustion products:

1. Gross Calorific Value (GCV):

   • GCV, also known as higher heating value (HHV), includes the total heat released during combustion, including the heat released by the condensation of water vapor in the combustion products.
   • GCV accounts for the latent heat of vaporization of water vapor produced during combustion. This means it includes the energy released when water vapor in the combustion products condenses back into liquid water.
   • GCV is typically expressed in units such as joules per kilogram (J/kg) or British thermal units per pound (BTU/lb).

2. Net Calorific Value (NCV):

   • NCV, also known as lower heating value (LHV), excludes the heat of vaporization of water vapor in the combustion products.
   • NCV assumes that the water vapor in the combustion products remains in a gaseous state and does not contribute to the heating value. Therefore, it does not account for the energy released by the condensation of water vapor.
   • NCV is typically slightly lower than GCV because it does not include the latent heat of vaporization of water vapor.
   • NCV is also expressed in units such as joules per kilogram (J/kg) or British thermal units per pound (BTU/lb).

In summary, the key difference between GCV and NCV is that GCV includes the latent heat of vaporization of water vapor in the combustion products, while NCV excludes it. Therefore, NCV is slightly lower than GCV because it does not account for the additional energy released during the condensation of water vapor.