A Simulation Study on Urea Maldistribution and Implications for NOx Reduction with a Multi-Channel Modelling Approach
Year: 2024
Type: article
Abstract: Urea-based selective catalytic reduction (SCR) is highly efficient for NOx abatement within a diesel aftertreatment system. However, abnormally high NOx emissions in the aftertreatment system tailpipe during WHSC (World Harmonized Steady-State Cycle) evaluation have been observed due to insufficient urea decomposition or mixing, which cannot be predicted by the current uniform 1D (one-dimensional) modelling approach with different urea dosing ratios. As a result, a multi-channel model has been developed to investigate the effect of urea maldistribution on aftertreatment system performance, where the uniformity index (UI) is used as a characteristic parameter to describe urea mixing efficiency. It was found that NOx emissions at the tailpipe can be successfully described with the multi-channel model even with a relatively high UI (UI = 0.95). Additionally, an improved segment UI factor as a function of mass flow rate has also been applied for maldistribution description, wherein better correlation with the measured NOx emission can be obtained.
Source: Applied Sciences
DOI: 10.3390/app142311105
Authors: Junyu Lang, Kewei Chen, Guoliang Su, Haoran Jia, Wenlong Tian, Shuzhan Bai, Ke Sun
Language: English
Topic: Engine and Fuel Emissions
Subfield: Automotive Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,728
OpenAlex ID: W4404793666