Effects of dual intake channels on energy efficiency and emissions of the uniflow scavenging opposed-piston engine

Uniflow scavenging opposed-piston two-stroke diesel engine has high power density and thermal efficiency. However, the uniflow scavenging performance control is inflexible and inefficient. In this study, the dual intake channels are proposed. The performance advantages and control methods of dual intake channels are explored by comparing the performance differences between single and dual intake channels under different conditions. The results show that the comprehensive performance of the dual intake channels is better than the single intake channel. Dual intake channels can improve energy efficiency and reduce NO_X emissions while maintaining ideal comprehensive performance. Under a single working condition of the dual intake channel, the air supply mass is reduced by 28.4%, and the NO emissions is reduced by 12%. For the dual intake channels, swirl intake channel pressure significantly affects scavenging efficiency, while straight intake channel pressure significantly affects the scavenging speed. Low intake port height ratio α and high straight intake channel pressure are more suitable for high-speed conditions, and high intake port height ratio α and low straight intake channel pressure are more suitable for low-speed conditions.