The key difference between net calorific value and gross calorific value is that net calorific value is the amount of heat that is created when water is converted into water vapor upon combustion of a material, whereas gross calorific value is the amount of heat created when water is converted into water vapor and back to the liquid state.
Calorific value is a parameter that is essential for the definition of the energetic content of different materials. We can call it generally as gross calorific value or as high heating value. The net calorific value, on the other hand, is the subtraction of the heat of vaporization of water vapor from the gross calorific value. The net calorific value is also known as the low heating value.
CONTENTS
1. Overview and Key Difference
2. What is Net Calorific Value
3. What is Gross Calorific Value
4. Net Calorific Value vs Gross Calorific Value in Tabular Form
5. Summary – Net Calorific Value vs Gross Calorific Value
What is Net Calorific Value?
Net calorific value is the subtraction of the heat of vaporization of the water from the high heating value. This parameter is also named the lower heating value (LHV) or as lower calorific value (LCV). This parameter usually assumes that the water component of a combustion process is occurring in the vapor state during the end of the combustion process. This assumption is the opposite of the gross calorific value (it assumes that all the water content in the combustion process occurs in a liquid state at the end of the combustion process.
When comparing different fuels, the net calorific value is more important than the gross calorific value. This is important when the condensation of the combustion product is not practical. Or else, it is important when heat at a low temperature cannot be put into any use.
Typically, in order to determine the net calorific value, we can use the European standard methods that use the gross calorific value. The gross calorific value is an experimental value. For this calculation, we need to know the oxygen, nitrogen, and hydrogen content of the sample. Moreover, the net calorific value depends on the dry mass of the sample.
What is Gross Calorific Value?
Gross calorific value is the amount of heat produced as a result of the complete combustion of a unit volume of a substance. It is the absolute value of the specific energy of combustion for a unit mass of a substance. It is a parameter that is essential in defining the energetic content of some materials. We can generally call it calorific value or high heating value. The unit of measurement for this parameter is KJ/kg.
It is very important to measure the gross calorific value of fuel or food because the efficiency of fuel or food depends on the calorific value. Therefore, the higher the gross calorific value, the higher the efficiency and vice versa. This means the gross calorific value is directly proportional to the efficiency. Moreover, the high calorific value represents the heat content of water vapor generated during the combustion process, and the substance recovers through different techniques and vice versa.
Difference Between Net Calorific Value and Gross Calorific Value
Calorific value is a parameter that is essential for the definition of the energetic content of different materials. There are two types as net and gross calorific value. The key difference between net calorific value and gross calorific value is that net calorific value is the amount of heat that is created when water is converted into water vapor upon combustion of a material, whereas gross calorific value is the amount of heat created when water is converted into water vapor and back to the liquid state.
The following table lists the difference between net calorific value and gross calorific value in tabular form.
Summary – Net Calorific Value vs Gross Calorific Value
Calorific value is a parameter that is essential for the definition of the energetic content of different materials. There are two types as net and gross calorific value. The key difference between net calorific value and gross calorific value is that net calorific value is the amount of heat that is created when water is converted into water vapor upon combustion of a material, whereas gross calorific value is the amount of heat created when water is converted into water vapor and back to the liquid state.
Reference:
1. “Calorific Value.” VEDANTU, Vedantu, 30 July 2020.
Image Courtesy:
1. “Calories” By Nick Youngson (CC BY-SA 3.0) via Blue Diamond Gallery