Effects of flow rate and equivalence ratio on syngas flames in a multi-nozzle micromix model combustor

In this paper, the flame structural parameters, OH* distribution characteristics, and dynamic behavior of the global heat release rate of a novel multi-nozzle micromix model combustor are experimentally investigated. The experiments were conducted at atmospheric pressure, high air temperature (691 K), equivalence ratio of 0.1–1.2, and air velocity of 30–80 m/s. The results demonstrate that the combustor has a wide operation window of stable combustion. The flame height is weakly related to air velocity and varies with equivalence ratio from 4D to 19D (D = 10 mm). The peak position of axial OH* intensity at the same flow rate keeps unchanged at various equivalence ratios, and the peak position of axial OH* increases in the range of 1.5D∼2.3D with increasing air velocity. The global heat release fluctuation of the flame becomes larger as the equivalence ratio decreases, which shows unsteady combustion behavior.