Technical Paper
Hydrogen Combustion using Port-fuel Injections in a Heavy-Duty Optical Diesel Engine Converted to Spark Ignition Operation
2023-09-29
2023-32-0043
This study examines the use of hydrogen as a fuel for internal combustion engines to decrease greenhouse gas emissions. The focus is on hydrogen combustion at leaner mixture conditions, which has the potential to increase efficiency and reduce NOx emissions. While metal engine experiments have established these benefits, there are only a few optical studies on pure hydrogen combustion under lean operating conditions. This study reports optical measurements performed in a heavy-duty optical diesel engine converted to spark-ignition operation with port-fuel injections and varying spark timing, at air-excess ratios (lambda) of 2.5 and 3. The engine was equipped with a flat-shaped optical piston that allowed for bottom-view imaging of the combustion process. High-speed natural combustion luminosity images were recorded, along with in-cylinder pressure measurements.