Simulation of Flameless Combustion of Natural Gas in a Laboratory Scale Furnace


Abstract: The purpose of this study is to characterise the flameless combustion of natural gas, experimentally, and by CFD modelling with FLUENT. Measurements performed in a laboratory scale furnace are used as boundary conditions and validation data for the various models tested. Turbulence and combustion are respectively modelled with the standard k-\varepsilon model and the Eddy-Dissipation model, combined with the Finite Rate model. Experimentally and numerically, the furnace presents 2 regimes of combustion according to the chamber temperature. The first regime is called the "near-lifted flame" regime; it happens with high furnace temperatures, when the kinetics do not limit the reaction. In that mode, there are 2 main reaction zones separated by the furnace axis. The second regime is called the "far-lifted flame" regime; it appears when the furnace temperature level is lower and the Arrhenius limitation slows down the reaction rate. In that case, the combustion zone is wider and farther from the base of the chamber. The present paper compares the measured and computed shapes of the reaction zone.

Keywords: Flameless combustion, Mild combustion, Numerical simulation, Diluted combustion

Full Text: PDF