An experimental investigation of fuel injection timing on NOx emission of marine slow speed engines

Abstract

At present, air pollution Annex to Marpol 73/78 convention is being compiled to regulate NOx and SOx emission limits. The paper describes the application of a CFD combustion model - KIVAII3v for a large bore, slow speed marine diesel engine and explores the feasibility of using fuel timing injection variables to estimate NOx exhaust emissions levels, at steady running conditions. The correlation analysis between the measured and calculated gaseous emission caused by fuel variable injection timing (VIT) was performed. The analysis is based on experimental data from Wartsila RTA engines test bed trials. Extracted and averaged measured history of NOx, and other gas components emission concentration were used as a comparison basis for calculation results. An examination of the measured and calculated results, particularly NOx concentrations, generally reveals a difference of emission levels associated with engine load and VIT setting.