Investigation of the effect of natural gas injection timing on dual-fuel engine emissions using split injection strategies

– Dual-fuel compressed ignition engine is the current favorite engine using diesel and natural gas as fuel. The cleaner emission gas produced is quite significant compared to dedicated diesel engines. Nevertheless, deficiencies are still found, such as when the engine operates at low load. It effects of less performance and exhaust emissions. The split injection is an alternative solution that can be implemented. Thse objective of this study is to identify the effect of split injection of natural gas with several split injection ratios and injection timings on exhaust emissions using a numerical method. The split injection of natural gas contributes to the reduction of exhaust emissions of NOx and CO in the first injection timing and the whole ratio, while the HC emissions increased slightly compared to single natural gas injection. Unfortunately, the indicated efficiency has decreased in earlier first injection timing. However, retarding first injection timing causes the concentration of CO and HC emissions to increase, while NOx emissions are less affected compared to natural gas single injection.