Numerical simulation of fluid flow and mixing process in a SCR denitration system

Abstract

Selective Catalytic Reduction (SCR) with ammonia is a key technology to reduce the NOx emissions from the coal-fired power stations. The denitration efficiency of SCR system depends on whether the flue gas and ammonia can get a good mix in the reactor. The fluid flow and the mixing process in a SCR denitration system have been analysed to gain an insight into the characteristic of the mixing process and to check the numerical simulation as a tool for the optimization design of the SCR system. Combined with the component transfer model and porous medium model, the large eddy simulation (LES) was carried out to portray the performance of the SCR system in a 310MW coal-fired station. Both the transient and time-averaged velocity fields and concentration fields in different cases were obtained. It has been found that mixing quality is improved significantly by incorporating a series of gate leafs.