Effects of Steam-Injection Strategies on Performance and Emission Characteristics of Marine Engines

In this study, the influence of direct steam injection (DSI) on the performance and emissions of marine engines is investigated. Simulation models are developed and tested based on experimental data. Steam is obtained by waste heat recovery in a marine engine. The limitations of DSI parameters are investigated based on the exhaust gas temperature. The steam quantity and temperature decrease with a decrease in load. The results show that steam mass plays an important role in NOx reduction and improving power. For a steam/fuel ratio of 1.27 at 100% load, the brake power improved by 3.09% and NOx emissions decreased by 4.67%. A higher degree of improvement is obtained with an increase in steam mass. The steam temperature and injection timing only slightly influenced the brake power and NOx emissions. When steam-injection timing improved to 12 degrees CA at 100% load with injection duration decreasing from 85 degrees CA to 25 degrees CA, brake power improved from 3,485.7 to 3,529.7 kW. All of this demonstrates that the DSI approach has excellent energy-saving and emission reduction potential for marine engines. The steam-injection strategy should be optimized in the future. (c) 2023 American Society of Civil Engineers.

Automated summary

This study investigates the impact of direct steam injection (DSI) on the performance and emissions of marine engines using simulation models based on experimental data. Steam is generated through waste heat recovery in a marine engine. The study explores the limitations of DSI parameters based on exhaust gas temperature and reveals that steam mass is crucial for reducing NOx emissions and enhancing power. The findings demonstrate the energy-saving and emission reduction potential of the DSI approach for marine engines, emphasizing the need for optimizing the steam-injection strategy in the future.