Study On Reaction Mechanisms And Numerical Simulation Of SCR Catalytic Converter

Selective catalytic reduction of NO_X(SCR), as an high efficiency way for eliminating NO_X, has began used to reduce NO_X in exhaust gas from floating diesel and its research and design should be paid more attention. The design of a SCR catalytic converter is a complex process involving the consideration of spray droplet distribution, flow of gas, reaction, heat transfer and so on. All of those processes have direct relation with catalyst and the structure of catalytic converter. In this paper these were analyzed and studied from the point of view of chemical reation, flowing gas and heat transfer.Giving the momentum conservation equation by the Darcy equation, simplify the process of the gas flowing, the species transport model and the heat transfer, become the 3-D problem to 1-D problem, distribute those 1-D conservations by Finite Volume Method (FVM), then program the computer by FORTRAN, Under-relaxation technique is used for gaining a convergence of the problem, the mass distribution of gas components in the channel and the temperature distribution in the catalyst are obtained both for steady and un-steady by this 1 -D model at last.Another model is build by Fire for argueing the 1-D simplified model. From compareing the result obtained by the simple model to the result obtained by Fire, it can find that the 1-D simllified model's result accord with Fire.Combine the 1-D simplified model and optimization software, the chemical kinetic parameters are obtained based on experiment. Those parameters can be used for simulating and designing catalytic converter which have complex structure.