Coupled sulfur/nitrogen fired-heater stack-loss balance
RefineryHydrotreatingSulfurNitrogenFiredHeaterStackLossBalance combines the
wet-flue-gas molar flow from a qualified combustion receipt with caller-owned
stack temperature, reference temperature, and mean wet-flue-gas molar heat
capacity. The immutable receipt returns every input and reconciles the sensible
stack loss to the total furnace loss already qualified upstream.
With wet flue gas in kmol/h, mean heat capacity in kJ/(kmol K), and temperature difference in K, the unit-explicit equations are:
stack sensible loss [MW] = wet flue gas * mean Cp * (stack T - reference T) / 3,600,000
total furnace loss = stack sensible loss + residual furnace loss
RefineryHydrotreatingSulfurNitrogenFiredHeaterStackLossBalance stackLoss =
RefineryHydrotreatingSulfurNitrogenFiredHeaterStackLossBalance.calculate(
combustion, stackTemperatureK, referenceTemperatureK,
meanWetFlueGasCpKiloJoulePerKmolKelvin);
double sensibleLossMw = stackLoss.getStackSensibleLossMegaWatt();
double residualLossMw = stackLoss.getResidualFurnaceLossMegaWatt();
double fractionOfFuel = stackLoss.getStackLossFractionOfFuelChemicalPower();
For the public 1000 kg/h DOE/OEDI Big Hill material case, the qualified combustion receipt produces 55.139015119 kmol/h wet flue gas and the qualified utility receipt assigns 0.153850948 MW total furnace loss. Illustrative caller inputs of 473.15 K stack temperature, 298.15 K reference temperature, and 34.0 kJ/(kmol K) mean wet-flue-gas heat capacity give 0.091132539 MW stack sensible loss, 0.062718410 MW residual furnace loss, and 8.885145634% of fuel chemical power assigned to stack sensible loss. These values qualify the arithmetic only; they are not defaults, measurements, recommendations, or fitted furnace correlations.
The NIST Chemistry WebBook publishes gas-phase heat-capacity and enthalpy relations for combustion-gas species. U.S. Department of Energy process-heating guidance identifies flue-gas or stack loss as heat leaving with combustion gases and relates waste-heat opportunity to exhaust-gas temperature and flow. Those public sources establish the engineering context only: this receipt does not embed species coefficients, temperature-dependent integration, or a site heat-capacity value.
The receipt fails closed if the caller’s sensible-loss scenario exceeds the qualified total furnace loss. It does not predict stack temperature, derive mixture heat capacity, model radiation or convection, calculate dew point or corrosion, represent draft or pressure drop, size heat-recovery equipment, estimate recoverable heat, or optimize furnace operation. Those effects require independent engineering qualification.
Sources accessed 2026-09-26: