Modeling and Numerical Simulation of Diesel Engine SCR Deposit

With increasingly stringent emission regulations for diesel engines, the SCR (selective catalytic reduction) technology has become the optimal choice to meet the stricter emission standards. But in the practical operations, the rapid change of engine working conditions leads to a rapid change of exhaust temperature, space velocity (SV) and urea dosage rate, which makes urea was difficult to complete evaporation and decomposition and result deposits formation on the exhaust pipe wall. In order to solve this problem, a component-level of SCR deposit model is proposed to describe the process of the spray, atomization, evaporation, decomposition and wall film formation. The model can be used for the system structure optimization and urea deposits control. Based on this model, the residual proportion and component of deposits under different boundary conditions are obtained, which can provide theoretical support to the reduction of deposits.