Flame propagation velocity in 2-stage gas combustion system applied in SI engine

International Automotive Conference 2018

Bueschke, W.^1 ; Skowron, M.^1 ; Szwajca, F.^1 ; Wislocki, K.^1

Poznan University of Technology, Piotrowo Street 3, Poznan

60-965, Poland^1

关键词: Combustion pro-cess;    Dynamic observation;    Dynamic registrations;    Flame propagation velocity;    Heat Release Rate (HRR);    High-speed recording;    Rapid compression machine;    Thermodynamic parameter;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/421/4/042009/pdf
DOI  :  10.1088/1757-899X/421/4/042009

来源: IOP

【 摘 要 】

Ever stronger emission standards accepted for modern internal combustion engines force some new tendencies in the engine development trends. In recent studies it was confirmed, that the use of combustion of lean gas-air mixtures leads to reduction of CO2 and HC emissions while maintaining a possible acceptable value of thermal efficiency. Such combustion systems, already known since many years as e.q. Turbulent Ignition, Pulsed Jet Combustion, Sparking Jet Ignition and similar, can offer further potential in the improvement of combustion process control. The main purpose of this research was to detect and define any correlation between gas delivery parameters, ignition energy in the first stage of combustion and some system design parameters with the turbulent ignition possibilities of lean and very lean gas mixtures, with the flame propagation velocity in main chamber and with the intensity of heat release. Such correlation should deliver some answers for the combustion system optimization and better combustion process control. For the above mentioned purpose the test stand with the model of IC engine was adopted. It delivered the possibilities of the spark-plug ignition in the prechamber and of the dynamic observation of the ignition spray propagation in main chamber of the system. For this last task the Rapid Compression Machine has been applied equipped with the optical access into main chamber and with high-speed recording system for dynamic registration of spray formation as well as for flame propagation across the chamber. Simultaneously performed indication of both chambers (pre-chamber and main chamber) made it possible to correlate of indexes determined for flame propagation velocity, flame luminosity distribution in main chamber with thermodynamic indexes achieved form the analysis of the pressures, temperatures and mixture masses in both chambers. The results achieved within this research allow to identify many design parameters of the 2-stage combustion system and to recognize more important thermodynamic parameters of the system which seems to be essential for improving of the system potential according heat release, heat release rate and system thermal efficiency for the future development.