1D thermo-fluid dynamic modelling of de-NOx SCR systems for diesel engine exhaust gas after-treatment. (5th May 2006)

• Record Type: Journal Article
• Authors: Montenegro, G.; Onorati, A.
• Is Part Of: International journal of vehicle design. Volume 41:Number 1/2/3/4(2006)
• Page Start: 285
• Page End: 306
• Publication Date: 2006-05-05
• Subjects: 1D unsteady flows -- reacting flows -- selective catalytic reduction -- thermo-fluid dynamic modelling -- diesel engines -- exhaust gas after-treatment -- vehicle emissions -- CFD -- computational fluid dynamics; Motor vehicles -- Design and construction -- Periodicals; 629.231
• Languages: English
• ISSNs: 0143-3369

Abstract

A 1D thermo-fluid dynamic computational model has been developed to simulate the unsteady reacting flows inside the SCR (Selective Catalytic Reduction) after-treatment systems of diesel engines. The standard SCR reaction, extended with a detailed NH3 adsorption and desorption mechanisms, and two reactions of urea decomposition, namely the thermolysis and hydrolysis, have been taken into account. Calculations under steady-state conditions have been carried out to validate the urea decomposition model, showing a good correlation with the experimental results available in the literature. The adsorption/desorption model has been validated as well, using different catalysts available on the market and comparing the results with experimental measurements. Furthermore, a diesel engine configuration has been considered to test the SCR model under different operating conditions, to point out the effects of flow unsteadiness over the de-NOx efficiency and also the risk of ammonia slip at the outlet of the SCR device.