Development of a lean premixed-type combustor with a divergent flameholder for a hydrogen-fueled micro gas turbine

摘要

Determining the cause of the flash-back of a hydrogen combustor using a lean premixed swirling flame for the hydrogen-fueled micro gas turbine and improving the combustor were required to achieve stable operation of the gas turbine during the starting period. A divergent-type flameholder for the gas turbine was developed, and the flame behavior and the flow field near the flameholder were examined to meet these requirements. The findings show that since the flame-attaching point fixed on the flameholder rim was insensitive to pressure fluctuation in the combustor by limiting the reverse flow region far downstream of the combustor entrance throat, the lean premixed flame never flashed back at low equivalence ratios. The hydrogen-fueled micro gas turbine with the improved prototype combustor achieved self-sustained operation due to smooth start-up. Excellent combustion performance of the micro gas turbine was obtained.