Estudo de caso: simulação numérica de um queimador de caldeira de CO

Abstract

Boilers that use carbon monoxide (CO) as fuel have shown high rates of nitrogen oxide (NO_x) emission. Currently, the formation of seven gases formed by the group of NOx is known, two of them are relevant when it comes to atmospheric pollution, nitrogen dioxide (NO_2) and nitrogen monoxide (NO). Processes that undergo combustion when in contact with atmospheric air transform NO molecules into NO_2, so the emission rates of this gas have been quite high, bringing concern to public bodies and organizations. A solution that has been studied and has shown good results is the staging of injected fuel in boilers, that is, gradual injection of fuel or oxidant. However, it is necessary at this point to evaluate the process in more detail to optimize the strategy, as well as to study the stators, which is where the fuel is injected into the carbon monoxide boilers, which may lead to the need to adopt modifications. to decrease the amount of NO_x generated in the process. In this research project, computational modeling is applied in order to allow a detailed analysis of turbulent flows and their physical properties inside the stators and at their exit. The mathematical modeling, composed by the mass conservation, linear momentum transport and energy balance equations, are discretized using the finite volume method and the transport equations are implemented in a block-structured mesh environment.