Prediction of Soot Emissions in Gas-Turbine Combustors

From a large number of experimental data, a formulation was developed for predicting the smoke number (SN) as measured in gas-turbine exhausts according to the well-established SAE standard. Three different scales of the same combustor were used with inlet temperature and pressure ranging from 300 to 600 K and from 0.1 to 0.9 MPa, respectively. The formulation is based on the residence time that is calculated from the mass flow rate, density, and the volumes of the primary and secondary zones of the combustor. The reaction rate has an Arrhenius form with the equivalence ratio to take into consideration the air and fuel flow rates. All of the required parameters can be evaluated from desired operating conditions. Nineteen different types of fuel were used, varying from a paraffinic mixture to a pure aromatic compound. With this wide range of fuels burned in the experiments, giving a SN variation from 0 to 100, the accuracy of the prediction is acceptable for most purposes. (Author)