CFD simulations to research the control rules with gate leaves in SCR-DeNOx facility for marine diesel engines

NOx is one of the major pollutants from marine diesel engine, and needs to be minimized. Selective Catalytic Reduction (SCR) with ammonia is a promising approach to reduce NOx emissions with the aim of meeting stringent emission regulations. The velocity distribution at the entrance of catalyst layers, which can be affected by the position, the size and the angle of the gate leaves, is one of the key factors on NOx removal efficiency of SCR systems. In this paper, gate leaves were divided into three groups and the surface at the entrance of the catalyst layers was divided into three regions which are influenced by gate leaves. The control rules of gate leaves angle were built based on CFD simulations in SCR-DeNOx system of the marine diesel engine (MAN 6S50MC-C) which worked in 100% loading. And then, simulations in the 75% working condition are carried out to verify the control rules.