Numerical investigation of the steady flamelet approach under different combustion environments

Application of the steady flamelet model on a lab-scale and an industrial furnace for different oxygen concentrations

“…It was found that the realizable k-epsilon model predicts temperature and species concentrations in close accordance to the RSM (Reynolds stress model) [57] and is therefore sufficient for the lab-scale application (see Ref. [55]). Spatial discretization of the scalars was done by the second order upwind scheme and PRESTO!…”

“…Operating conditions between 21 and 45 vol% were investigated in detail because higher increase of the flame temperature and furnace efficiency is expected in this range (see Refs. [9,55]). Operating pressure in the furnace was approximately 0.3 mbar higher than ambient pressure to avoid air leaking in oxygen enriched combustion.…”

“…In times of increasing computer power, numerical tools like CFD are used to predict the effect of oxygen enrichment on the production rate and avoid expensive test runs at the same time. A numerical and experimental study of the increase in furnace efficiency due to oxygen enriched combustion was done by Prieler et al [55]. They measured and simulated the heat transfer to the furnace load and highlighted the increase of furnace efficiency as well gas savings in a range of 25e100 vol% O 2 in the oxidizer.…”

The usability and limits of the steady flamelet approach in oxy-fuel combustions

“…With increasing oxygen concentration in the oxidizer the energy efficiency increased from 60% at 21% O 2 to 78% at 38% O 2 . Numerical calculations and experiments carried out on a lab-scale furnace with a thermal load by Prieler et al [9] also showed an increase of the efficiency from 44% at 25% O 2 to 67% at 100% O 2 . In conventional power generating processes, the maximum temperature is limited through high stresses, i.e.…”

The Control of Pollutant Emission from Syngas Flames Using the Oxidizer Dilution Approach

“…For combustion modelling, we use the steady laminar flamelet approach [12][13][14][15][16][17][18][19] in which the laminar flamelets are pre-computed via the detailed kinetic scheme of Qin [20]. The transport equations for the first two moment of mixture fractions are given by…”