Technical Paper
Improvement in Oxy-fuel Combustion of SI Engine Fueled by Natural Gas
2023-09-29
2023-32-0085
Oxy-fuel combustion (OFC), in which fuel is burnt with pure oxygen, is a promising method by which to establish a CO2 recovery system from engine exhaust. The ideal exhaust gas for OFC consists of only CO2 and H2O at a stoichiometric mixture ratio, which can be easily separated by cooling the exhaust. In OFC, exhaust gas recirculation (EGR) is applied in order to avoid an extreme increase of the combustion temperature by increasing the heat capacity. In the present study, in order to improve the OFC of a natural-gas spark-ignited engine, the effect of the operating conditions on the combustion characteristics was investigated using a rapid compression and expansion machine. The effects of the compression ratio, ignition timing, and CO2 concentration in the mixture were examined while keeping the fuel-oxygen mixture at the stoichiometric ratio.