Demonstration of High Compression Ratio Combustion Systems for Heavy-Duty Diesel Engine with Improved Efficiency and Lower Emissions
2022-01-0505
03/29/2022
- Event
- Content
- Advanced diesel combustion systems continue to push the peak cylinder pressure limit of engines upward to allow for high efficiency combustion with high compression ratios (CR). As indicated by the air-standard Otto and Diesel cycles, increased compression ratios lead to higher cycle efficiency. The study presented here describes the development and demonstration of a high-efficiency diesel combustion system. The study used both computational and experimental tools to fully develop the combustion system. Computational fluid dynamics (CFD) simulations were carried out to evaluate combustion with two combustion systems at a compression ratio of 22:1: the first was based on the Volvo Wave piston design and the second was a stepped-lip piston design that provides similar spray recirculation characteristics. Analysis of combustion performance and emissions was performed to confirm the improvements which these piston designs offered relative to the baseline combustion system for the engine. Companion single-cylinder engine (SCE) experiments were performed to validate the simulation results. The combustion profiles showed good agreement between the experimental and computational results. Indicated thermal efficiency was increased by almost 1.0% point with the high compression ratio pistons. Further testing on a multi-cylinder engine verified this improvement in the engine brake thermal efficiency. Discussion of the performance differences between the two combustion systems evaluate the comparative advantages and disadvantages of each system. Potential opportunities for further gains are then presented.
- Citation
- Cung, K., Bitsis, D., Briggs, T., Miwa, J. et al., "Demonstration of High Compression Ratio Combustion Systems for Heavy-Duty Diesel Engine with Improved Efficiency and Lower Emissions," SAE Technical Paper 2022-01-0505, 2022, .