Hydrogen enhancement on a mesoscale swirl stabilized burner array

This manuscript presents a study of hydrogen-enhanced methane flames in a compact mesoscale burner array, where even a minute addition of hydrogen can significantly improve flame stability with reduced combustion length scale thereby enabling volumetric flexibility in small-scale combustion systems. The effect of hydrogen enhancement is demonstrated through combustion reaction length scale and operation limit analysis using methane fuel. The added hydrogen lowered lean blow off equivalence ratios, increased flame temperatures, and shorten the flame length scale, ultimately producing a denser flame array. 10 kHz OH* chemiluminescence and OH planar laser induced fluorescence imaging techniques were used to estimate heat release rate and visualize flame structures. Hydrogen addition increased the OH intensity and decreased global heat release rate fluctuation, and also showed more stable operation under acoustic perturbations. Hydrogen enhancement can be a promising solution for reducing geometric constraints and improving operating capabilities for compact propulsion and power generation systems. (c) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.