Study on the Effects of Exhaust Gas Recirculation and Fuel Injection Strategy on Transient Process Performance of Diesel EnginesWenyu Gu, Wanhua Su
- Management, Monitoring, Policy and Law
- Renewable Energy, Sustainability and the Environment
- Geography, Planning and Development
- Building and Construction
To meet increasingly stringent emission regulations, this study investigates the transient process of a heavy-duty diesel engine equipped with a two-stage turbocharger. The study focuses on analyzing the impact of the EGR system and fuel injection strategy during a transient process of a load increase (20% to 100% in 1 s) at a constant speed (1300 rpm). The research results showed that delaying the opening time of the high-pressure EGR valve from 0.1 s to 0.5 s reduces peak carbon soot emissions by 51.3%, with only a 3.13% increase in NOx emissions. By extending the high-pressure exhaust gas recirculation mixing length, the issue of an excessively high fuel–oxygen equivalence ratio caused by uneven exhaust gas mixing in individual cylinders can be avoided, resulting in a maximum reduction of 47.0% in peak soot emissions. Building on exhaust gas recirculation optimization, further modifications to the main and post-injection strategies led to a 28.1% reduction in soot emissions, a 4.73% decrease in peak NOx emissions, and a minor increase of 1.87% in the indicated fuel specific consumption compared to the single-injection strategy. The significant reduction in soot emissions will provide benefits for public health and environmental sustainability.