PR-309-20201-R01 CFD Study of Prechamber Ignition Mechanisms for GHG Reduction

Pre-Combustion Chambers (PCCs) are commonly used in large-bore natural gas engines to improve the repeatability of ignition and the completeness of combustion, particularly when the engine operates near the lean limit. A study of the ignition of the MCC in a Cooper-Bessemer GMV two stroke lean burn natural gas engine was conducted using Converge CFD software to provide design parameters that will aid PCC manufacturers in improving combustion and reducing methane emissions. The effects of temperature and chemical intermediates (sometimes called “radicals”) were investigated, as well as the combination of thermal and intermediate effects. Additionally, this study examined the effect of MCC mixing on the completeness of combustion. This was initially examined as complete fuel-air mixing, and then as a completely mixed Main Combustion Chamber (MCC), with chemical intermediates mixed with the fuel and air to ignite the MCC. This study contributes an important first step in understanding how a PCC ignites the MCC and gives the reader a guide to selecting upgrade technologies when examining fuel injection systems and PCC configurations.