Computational Investigation of In-Cylinder NOX Emissions Reduction in a Large Marine Diesel Engine Using Water Addition Strategies

In the present work, the effects of water introduction in a large two-stroke marine diesel engine operating at full load are studied via Computational Fluid Dynamics, utilizing a modified version of the KIVA-3V code. The impact of two techniques, namely intake air fumigation and Direct Water Injection (DWI) on pollutant emissions and Specific Fuel Oil Consumption (SFOC) is investigated. It is concluded that DWI is more effective in reducing NO_x emissions; however, its performance in terms of soot emissions and SFOC is inferior. The analysis shows that the 2016 NO_x emission standards set by the International Maritime Organization, dictating an 80% reduction, could be met with water addition strategies. The present results demonstrate the potential of water addition techniques, and suggest that a substantial improvement of engine operation with optimized water addition strategies may be feasible.