Stoichiometric Combustion

Overview

Engineering reference data for Stoichiometric Combustion 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 with Excess Air

The chemical equation for methane burned with 25% excess air is:

$CH_4 + 1.25 \times 2(O_2 + 3.76 N_2) \rightarrow CO_2 + 2 H_2O + 0.5 O_2 + 9.4 N_2$

The following table provides approximate values for CO₂ and O₂ in the flue gas as a function of excess air for various fuels.

Interactive Charts

References

• Original Source