Combustor modeling and design modification of a micro gas turbine with a rotating casing for H2-rich syngas fuel

The primary constituent of syngas is H2 and CO. The content of H2 plays a significant role in combustion characteristics of syngas. The effects of H2 content in syngas combustion with rotating casing have been previously studied. This study used the modeling as a design tool to verify the combustor performance for H2-rich syngas fuel. The modeling was performed with 3-D compressible k- realizable turbulent flow model and presumed probability density function for combustion process invoking a laminar flamelet assumption generated by detailed chemical kinetics from GRI 3.0. The combustion characteristics and NOx emissions were investigated to understand the rotating effects of H2-rich syngas combustion in the modified design of can combustor. In the modified design, the high-temperature flame gets stabilized towards the wall of the combustor. Unlike in previous design, the high-temperature flame moves towards the exit of the combustor. The exit temperature and pattern factor dropped and reached the design requirements after the modification. The rotation of casing enhances the swirling strength, which benefits proper mixing of fuel and air, which leads to reduction in pattern factor and NOx emissions.