Computational Fluid Dynamics (CFD) Simulation of Fuel Gas and Steam Mixtures to Decrease NOx Emissions of Industrial Burners

摘要

Nowadays, there is a great concern about the NOx emissions from combustion processes due to the adverse effects on health. The NOx emissions are avoided in high flow rate industrial combustion exhaust gases by reaction with ammonia. For the other cases, simpler solutions are proposed and studied using CFD, such as exhaust gas recirculation or improving the burner design. The present study is focused on reducing the NOx by the presence of steam. The presence of steam decreases a bit the peak temperature and greatly affects the reaction mechanism, decreasing the amount of NOx produced. Chemical industry heating services are provided by steam and therefore it is readily available. The introduction of steam in the combustion chamber together with the fuel of the air is a simple and cheap option to decrease NOx emissions. A CFD analysis is provided in the present study, showing that steam addition effect is more intensive when added to the fuel, than added to combustion air. When 25% steam is added in fuel, the quantity of NOx almost halves in comparison to the dry case.