Electronic Science and Technology ›› 2022, Vol. 35 ›› Issue (6): 89-94.doi: 10.16180/j.cnki.issn1007-7820.2022.06.0014

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Numerical Analysis of NOx Conversion Efficiency of SCR Catalytic Converter of Diesel Engine

ZHAO Hao,HE Wei   

  1. Faculty of Mechanical and Electrical Engineering,Kunming University of Science and Technology,Kunming 650500,China
  • Received:2020-12-23 Online:2022-06-15 Published:2022-06-20
  • Supported by:
    National Natural Science Foundation of China(51168020);Yunnan Applied Basie Research Project(2013FZ024);Kunming University of Science and Technology Testing Foundation(2019M20182103041)

Abstract:

In order to explore the influence of the temperature of cyclone mixer and urea injection flow rate on NOx conversion efficiency, CFD technology is used to study the SCR catalytic converter for a diesel engine by chemical reaction and steady flow numerical simulation. By changing the temperature of the cyclone mixer and the urea injection flow rate, the concentration and uniformity coefficient of NH3 and the mass fraction of NOx at the outlet are compared under different conditions. The results show that the mass fraction distribution of NOx at the outlet of SCR catalyst presents the law of low center and high edge, and the temperature change of cyclone mixer has little effect on the uniformity coefficient of NH3 velocity. When the temperature is 400 ℃, the NH3 distribution is more uniform, the NH3 generation rate and NOx conversion efficiency are higher. These results indicate that the NOx conversion efficiency and urea utilization rate can be improved by selecting the appropriate urea injection flow rate.

Key words: diesel engine, SCR, CFD, selective catalytic reduction, numerical modeling, uniformity coefficient, NOx conversion efficiency, utilization rate of urea

CLC Number: 

  • TP31