Optimization of exhaust emissions from marine engine fueled with LNG/diesel using response surface methodology

For accurately analyzing the emission performance of dual-fuel engine, an experimental scheme was designed based on response surface methodology, and the central composite design was applied to this study. Speed and load were used as the influencing factors, and NOX, CO, CO2, and HC were the corresponding responses. Data of dual-fuel engine emissions were utilized to set up mathematical model to analyze the emission characteristics of engine. Results of data analysis were found to match the original engine's emissions. The significance of the model test showed that P-values of mathematic model are less than 0.05, which verified the validity of the designed model. Speed of 800 r/min and load of 64% were found to have better emission performance with higher desirability of 65.4% for the tested engine. Corresponding emissions were 0.16% of CO, 3.97% of CO2, 463.92 ppm of NOX, and 224.27 ppm of HC.