Excess Air Calculation

Given the measured O2 percentage in the flue gas and fuel composition, this algorithm iteratively estimates the fraction of excess air supplied to the combustion process. The calculation uses stoichiometric relationships and mass balance.

The implementation uses the shared process_heat::calculateExcessAir function from the Process Heat Utilities namespace as the initial estimate, then iteratively refines it based on the fuel composition and measured flue gas properties.

Iterative Procedure

1. Initial Estimate: Uses process_heat::calculateExcessAir to get a starting excess air value based on measured flue gas O2. See Excess Air from Flue Gas O2 for the formula.
2. Iterative Refinement: Calculates expected O2 using solid_liquid_flue_gas_material::calculateFlueGasO2 and adjusts excess air until convergence (error < 2%).
3. Convergence: Iteration continues until the calculated O2 matches the measured O2 within tolerance.

Symbols

\(EA\)	Excess air fraction \([\unit{ \unitless}]\)
\(O_2\)	Measured flue gas oxygen percentage \([\unit{ \percent}]\)

See also

process_heat::calculateExcessAir for the initial excess air estimate formula

solid_liquid_flue_gas_material::calculateFlueGasO2 for O2 calculation during iteration