Q3Engineering Chemistry
Question
2 marks
Q.3 Define the term gross and net calorific value of a fuel.
Answer
Gross Calorific Value (GCV) represents the total theoretical heat strictly produced including the latent heat of condensed water vapor, whereas Net Calorific Value (NCV) mathematically excludes this latent heat, representing the actual usable heat in practice.
The Calorific Value fundamentally defines the absolute thermodynamic energy quality of a combustible fuel.
- Gross Calorific Value (GCV): Also rigidly termed Higher Calorific Value (HCV). It is strictly defined as the absolute total quantity of thermal heat systematically liberated when exactly one unit mass of fuel is burnt completely, and the resulting hot combustion products are rigorously cooled entirely back down to room temperature ( or ). It mathematically includes the massive latent heat recovered when the produced steam physically condenses into liquid water.
- Net Calorific Value (NCV): Also strictly termed Lower Calorific Value (LCV). It rigorously represents the actual practical heat completely available when the hot combustion gases are permitted to physically escape directly into the atmosphere without cooling, meaning the latent heat of the steam is totally lost.