Optimization of fuel/air mixing and combustion process in a heavy-duty diesel engine using fuel split device

In order to improve the in-cylinder fuel/air mixing process of heavy-duty diesel engines, optimize the combustion process and reduce the soot emissions, a new device named fuel split device (FSD) was proposed. The related numerical research of the in-cylinder velocity fields, fuel/air mixing process, combustion performance and emission characteristics of a heavy-duty diesel engine at high load was performed. The numerical results showed that the FSD had a positive effect on improving fuel/air mixing process by splitting the fuel spray, which could increase air utilization and lead to efficient combustion. Firstly, the FSD had the ability to make a better utilization of fresh air by expanding the fuel injection area; secondly, the multi-vortex structure could be formed during the fuel injection process, which could greatly improve the fuel/air mixing process. Due to the improved fuel/air mixing process with the FSD, the combustion duration was shortened by 14 degrees CA, the indicated power delivery was increased by 6.5%, and the soot, HC, CO mass were finally reduced by 73%, 90% and 54%, respectively. It is suggested that the FSD, with its excellent combustion performance and low soot emissions, has a better application prospect in heavy-duty diesel engines.

Automated summary

The study shows that the fuel split device (FSD) can improve fuel/air mixing process by splitting fuel spray, increasing air utilization and enhancing combustion efficiency. The FSD expands fuel injection area and forms multi-vortex structure, resulting in improved fuel/air mixing process and reduced emissions.