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

• Published in: International journal of naval architecture and ocean engineering Vol. 7; no. 6; pp. 1020 - 1034
• Main Authors: Choi, Cheolyong, Sung, Yonmo, Choi, Gyung Min, Kim, Duck Jool
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.11.2015; De Gruyter Open; Elsevier; 대한조선학회
• Subjects: Compact design; NOx reduction; reduction; Selective catalytic reduction; Uniformity index; Urea decomposition; 조선공학; Compact design; Urea decomposition; Uniformity index; Selective catalytic reduction; NOx reduction
• ISSN: 2092-6782; 2092-6790; 2092-6782
• DOI: 10.1515/ijnaoe-2015-0071

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. NH3 conversion was maximized in the zone due to widely distributed turbulence intensity and high value of uniformity index. It caused improvement of NOx reduction efficiency of the system. It was possible to reduce 55% length of the chamber and connecting pipe without decrease of NOx reduction efficiency.