Numerical Study on the Role of Density and Diffusivity for Urea Gas Decomposition in Urea-SCR

다국어 초록 (Multilingual Abstract)

The understanding of urea gas decomposition process is an important step to simulate a urea-SCR system. In this study, a three-dimensional model with the laminar flow of an incompressible viscous gas at a steady-state by the SIMPLE algorithm is developed to simulate the urea gas decomposition in a urea-SCR system by computational fluid dynamics (CFD) method. The process of urea gas decomposition is calculated by the modification of source terms in the species transport equation. A porous medium coated by metal-based catalyst is included in the simulation without the calculation of NOx reduction and NH₃ oxidation processes. Diesel exhaust gas is simulated by solving the three-dimensional Navier-Stokes, mass conservation, chemico-thermal enthalpy and species transport equations coupled with the themophysical equations for mixture properties. The purpose of this study is to investigate the role of diffusivity and density on the process of urea gas decomposition in a urea-SCR system. It is found that the density has stronger influence at low temperature ranges in the process of urea gas decomposition and the diffusivity has stronger influence at the high temperature ranges.

목차 (Table of Contents)

• Abstract
• 1. INTRODUCTION
• 2. NUMERICAL ANALYSES
• 3. RESULTS AND DISCUSSION
• 4. CONCLUSIONS
• ACKNOWLEDGMENTS
• REFERENCES