The research on dynamic performance of single channel selective catalytic reduction system with different shapes

Abstract

This work tried to improve the denitration (de-NOx) performance of the selective catalytic reduction (SCR) system by changing the structure of the channel, and identify the factors affecting SCR catalytic reaction. A single channel in the catalytic converter is selected as the research object and a three-dimensional internal flow model is established. Firstly, the simulation results are compared with the experimental results to verify the reliability of the model. Secondly, the flow, species transfer and catalytic reaction in a single channel with different cross-section shapes are simulated and compared comprehensively. The results show that changing shape of the channel can improve the de-NOx performance and decrease the pressure drop. At the inlet velocity of 20 m/s, the circular channel has the largest NOx conversion efficiency (66.2%) and is 0.61% higher than that of the square channel. The pressure drop of circular channel is the smallest, which is 50 Pa less than that of the square channel. Finally, using channel shape, inlet velocity and NO2/NOx as the optimal variables, the orthogonal experimental design has been made. The results show that the influence of inlet velocity on NOx conversion efficiency and pressure drop is the most significant. The combination of the highest NOx conversion efficiency is the inlet velocity of 10 m/s, corrugated plate row, and NO2/NOx ratio of 0.5. The research on the single channel flow and reaction can provide theoretical and engineering reference for the subsequent research on multi-channel flow and reaction characteristics in the real SCR system.