CFD OpenFOAM: implementação da combustão smouldering e sua avaliação paramétrica

Abstract

Smouldering is a slow, low-temperature, flameless form of combustion that occurs at rel-atively low temperatures. It is supported by the heat released in heterogeneous reactionsresulting from direct attack of oxygen on the surface of solid fuels. Despite the relatively lowcharacteristics, it constitutes a significant hazard. This work aimed to evaluate the smol-dering combustion of oil shale in a combustion cell. The open-source software OpenFOAMwas used together with the solver biomassGasificationFoam, designed for thermochem-ical conversion processes of solid fuels in a fixed bed. The results were compared withexperimental data from literature. It was also analyzed the importance of oxigen supply tothe combustion front velocity. Finally, a parametric study was conducted to evaluate theinfluence of physical parameters in the evolution of bed temperature and combustion frontvelocity. The temperature profiles showed good agreement with the experiments. It wasfound that the temperature of the solid and gas phases have different values, characterizingthe local thermal non-equilibrium. Moreover, it was possible to confirm the reaction leadingcombustion structure, where the reaction zone moves more quickly than the heat transferzone