Entrained flow gasification. Part 2: Mathematical modeling of the gasifier using RANS method

CFD (RANS based) simulations of REGA-1 experimental campaign concerning gasification of glycol in an oxygen-nitrogen mixture have been carried out. The reacting flow-field has been computed using a number of turbulence models while turbulence-chemistry interactions have been modeled using either the Eddy Dissipation Concept (EDC) or the presumed PDF approach. Two global-chemistry schemes have been used: the (HVI1) scheme for glycol gasification and the extended Jones-Lindstedt scheme. Radiation has been computed using the Discrete Ordinate Method with a comprehensive analysis concerning absorption/emission of infrared radiation by gaseous molecules as well as absorption and scattering on droplets. The CFD-predictions of the near-atomizer region have been sensitive to and strongly dependent on the sub-models used; the spray sub-model and the chemical schemes are the most important. Good quality predictions of temperature and chemical species ($\text{CO}$, $\text{H}_2$, $\text{CO}_2$, $\text{H}_2$ $\text{O}$, $\text{CH}_4$) concentrations at 300 mm and 680 mm distances from the atomizer have been obtained. The HVI1 global chemistry scheme has predicted very well not only the $\text{CO}$/$\text{CO}_2$ ratios but also the trace concentrations of methane. ... mehrThe paper shows how to simplify the radiative heat transfer simulations without a significant loss in accuracy.