Experimental study on flow structure of a swirling non-premixed syngas flame

The development of integrated gasification combined cycle (IGCC) systems provides cost-effective and environmentally sound options for meeting the future coal-utilizing power generation needs in the world. The combustion of gasified coal fuel significantly influences overall performance of IGCC power generation. Experiments are performed to investigate the characteristics of syngas swirling flame using the particle image velocimetry (PIV) in this paper. With the increase of CO/H₂ molar ratio, the distance between the nozzle and the fuel vortex in flame increases at first, and then reduces slowly; maximum of the axial mean velocity increases continuously, but the axial mean velocity peaks on the side of centerline change little. The experiment indicates that with the increase of fuel to air velocity ratio, the fuel vortex grows up at first, and then becomes thinner; the distance from the fuel vortex to the nozzle reduces at first, and then increases; inner boundary of the recirculating zone increases. Furthermore, difference between the methane swirling flow field and the syngas swirling one is analyzed in this paper. It can establish the benchmarks for the development and validation of combustion numerical simulation by the data from this experiment.