Technical Paper
Numerical Study of an EGR Dilution in a Pre-Chamber Spark Ignited Engine fuelled by Natural Gas
2024-04-09
2024-01-2081
Exhaust gas recirculation (EGR) is a proven strategy for the reduction of NOx emissions in spark ignited (SI) engine and compression ignition engines especially in lean burn conditions where increase thermal efficiency is obtained. The dilution level of the mixture with EGR is in a conventional SI engine limited by the increase of combustion instability (CoV IMEP). A possible method to extend the EGR dilution level and ensure stable combustion is the implementation of an active pre-chamber combustion system. The pre-chamber spark ignited (PCSI) engine enables fast and stable combustion of lean mixtures in the main chamber by utilizing high ignition energy of multiple flame jets penetrating from the pre-chamber to the main chamber. The main feature of an active pre-chamber is the ability to control mixture dilution at the spark plug by adding an injector to the pre-chamber.