The flue gas properties (excess air, specific heat, and available heat) are calculated using the gas_flue_gas_material::processHeatProperties function. This function analyzes the fuel gas composition and operating conditions to determine key combustion parameters needed for heat recovery calculations.

Computed Properties

\(EA\)	Excess air fraction \([\unit{ \unitless}]\)
\(C_{p,flue}\)	Specific heat of flue gas \([\unit{ \btu\per\pound\degreeFahrenheit}]\)
\(AH\)	Available heat fraction (sensible only) \([\unit{ \unitless}]\)
\(SA_{req}\)	Stoichiometric air required \([\unit{ \standardCubicFeet\per\standardCubicFeet}]\)
\(HHV_{fuel}\)	Higher heating value of fuel \([\unit{ \btu\per\standardCubicFeet}]\)

Note: These properties are calculated by the gas_flue_gas_material::processHeatProperties function using gas composition, flue gas temperature, oxygen percentage, combustion air temperature, fuel temperature, ambient air temperature, and moisture in combustion air.