A novel computational scheme and its application for simulation of the flow characteristics of flue gas

In this paper, a novel computational scheme, local whole-information difference scheme (LWDS), was proposed to solve significant pseudo diffusion in recirculating flow zone during numerical simulation. In LWDS, the effect of all of the local around points on the control volume was considered to demonstrate the spatial characteristics of the flow, and the weighted value at each point is adjusted according to the local velocity field, so as to reduce the numerical diffusion. LWDS is with more accuracy than upwind and power difference schemes, and it is applied to compute the flow characteristics of air in a reactor. The results show that the flow characteristics in the reactor affect the mercury speciation distribution in the flue gas, and it also affects the mercury removal efficiency of the mercury sorbent and fly ash. The possible reasons are that different flow characteristics makes the contents in the flue gas be with different resident time in the reactor and affects the chemical reaction between the contents with mercury. In the multiphase flow reactor, when other conditions were same, four injection ports were with high mercury removal efficiency since it was with more uniform distribution of the sorbent in the flue gas.