Numerical simulation of double chemically reacting particles moving in hot O2/CO2 atmospheres

Abstract

The entrained-flow gasifier operates with large numbers of discrete particles, and an individual particle has an impact on the reactions of the particles nearby. Therefore, taking the double particles as an example to explore the conversion process offers a reference for developing sub-models that available for reactor-scale gasification simulation. In this study, a CFD-based model was developed to describe the reaction of double coal char particles in O2/CO2 atmospheres. The influence of Reynolds number and oxygen mole fraction on the flame morphology evolution, the Stefan flow, and the carbon consumption rate were discussed to understand the conversion of the double particles. The results show that the severe reaction area around the double particles gradually migrates towards the front of particle 1 with the increase of oxygen mole fraction, and the area of high-temperature zone decreases multi-modally with the increase of both factors. Reynolds number is the main factor affecting mass transfer. The overall carbon consumption rates of the double particles grow linearly with the increase of the oxygen mole fraction, and the rate of particle 1 is greater than that of particle 2. The Reynolds number has a greater effect on intensifying the difference between the carbon consumption rates of the double particles.