Abstract
In coal-fired thermal power plants, selective catalytic de-NOx system is widely used and very efficient method to reduce NOx emission from the plant. However, ash particles laden in flue gas adhere on a de-NOx catalyst surface, and ash coverage causes the severe degradation of de-NOx catalyst. Authors numerically investigated the effect of flow behavior in a honeycomb channel on the adhesion characteristics of particles to the wall in the previous study. However, previous study was performed under the assumption that all particles, which reach the wall, adhere. Therefore, in this study, the effect of particle collision and rebound behavior on the adhesion characteristics on the wall of honeycomb shaped catalyst was investigated by applying a direct numerical simulation (DNS). In order to take account of particle collision and rebound behavior, the probability coefficient of adhesion was introduced. The results show that although particle adheres on the wall only in the upstream region, in which flow condition is turbulent, irrespective of adhesion probability coefficient, the amount of adhered particles decreases with decreasing probability coefficient. The results also indicate that particle re-adhesion also occurs only in the upstream region even though some particle rebound and return to the flow from the wall.
