Fuels Air Flue Gas

Overview

Engineering reference data for Fuels Air Flue Gas in combustion engineering.

Key Formulas

Heat Release

$Q = \dot{m} \cdot HV$

Fuel energy release rate.

Air-Fuel Ratio

$AF = \frac{m_{air}}{m_{fuel}}$

Mass of air per mass of fuel.

Excess Air

$EA = \frac{O_2}{21 - O_2} \times 100\%$

From flue gas oxygen measurement.

Variables

Symbol	Description	Unit
$Q$	Heat release rate	W
$\dot{m}$	Mass flow rate	kg/s
$HV$	Heating value	J/kg
$AF$	Air-fuel ratio	—

Combustion Air and Flue Gas Data

The following table provides theoretical combustion air requirements and theoretical flue gas volumes for common fuels. All volumes are measured at standard pressure (1 atm, 0°C).

Units by Fuel Type

Fuel Type	Air (Metric)	Air (Imperial)	Flue Gas (Metric)	Flue Gas (Imperial)
Solids	m³/kg	ft³/lb	m³/kg	ft³/lb
Gases	m³ air/m³ fuel	ft³ air/ft³ fuel	m³ gas/m³ fuel	ft³ gas/ft³ fuel
Fluids	m³/liter	ft³/gal	m³/liter	ft³/gal

Important Notes

• Stoichiometric combustion: The data assumes complete (stoichiometric) combustion with no excess air
• Density relationship: Combustion of a fuel gas produces flue gas with higher density than both the original fuel gas and the combustion air
• Standard conditions: All volumes are measured at standard atmospheric pressure (1 atm / 101.325 kPa)

Interactive Charts

References

• Original Source