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http://dx.doi.org/10.1515/ijnaoe-2015-0071

Numerical analysis of NOx reduction for compact design in marine urea-SCR system  

Choi, Cheolyong (Graduate Program, School of Mechanical Engineering, Pusan National University)
Sung, Yonmo (Department of Mechanical Engineering, Imperial College London)
Choi, Gyung Min (School of Mechanical Engineering, Pusan National University)
Kim, Duck Jool (School of Mechanical Engineering, Pusan National University)
Publication Information
International Journal of Naval Architecture and Ocean Engineering / v.7, no.6, 2015 , pp. 1020-1033 More about this Journal
Abstract
In order to design a compact urea selective catalytic reduction system, numerical simulation was conducted by computational fluid dynamics tool. A swirl type static mixer and a mixing chamber were considered as mixing units in the system. It had great influence on flow characteristics and urea decomposition into ammonia. The mixer caused flow recirculation and high level of turbulence intensity, and the chamber increased residence time of urea-water-solution injected. Because of those effects, reaction rates of urea decomposition were enhanced in the region. When those mixing units were combined, it showed the maximum because the recirculation zone was significantly developed. $NH_3$ conversion was maximized in the zone due to widely distributed turbulence intensity and high value of uniformity index. It caused improvement of $NO_x$ reduction efficiency of the system. It was possible to reduce 55% length of the chamber and connecting pipe without decrease of $NO_x$ reduction efficiency.
Keywords
Selective catalytic reduction; Urea decomposition; Uniformity index; $NO_x$ reduction; Compact design;
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