Prediction of oxy-coal flame stand-off using high-fidelity thermochemical models and the one-dimensional turbulence model

An Eulerian one-dimensional turbulence (ODT) model is applied to simulate oxy-coal combustion, with specific aim at predicting flame stand-off distances. Detailed gas-phase chemical kinetics based on the GRI3.0 mechanism are utilized. A high-fidelity model for devolatilization is considered that predicts evolution of several light gas species as well as char as products of devolatilization. The mass, momentum and energy governing equations are fully coupled between the particle and the gas phase. Likewise, char oxidation and gasification are both considered. Results indicate that char oxidation and gasification are both significant during the later stages of devolatilization. The impact of radiative temperature and mixing rate on oxy-coal flame is simulated and discussed where flame stand-off is used as a metric to compare the simulation prediction with experimental data. The data show evidence that there is kinetic limitation to the flame standoff distance. Finally, results show that ODT can provide quantitative agreement with experimental data in predicting flame standoff in oxy-coal jet flames.