Effects of non-thermal plasma on turbulent premixed flames of ammonia/air in a swirl combustor

Abstract

The effects of non-thermal plasma (NTP) induced by a dielectric barrier discharge (DBD) reactor on the stability of turbulent lean and rich premixed ammonia/air flames and the NOx emission characteristics in a modified model gas turbine combustor are experimentally investigated by varying the applied AC voltage, VAC, frequency, fAC, and the mean mixture velocity, U0. Applying NTP to ammonia/air flames augments the flame stability such that the stable flame regime is extended to lower equivalence ratio, ϕ, under fuel-lean conditions or higher ϕ under fuel-rich conditions. NTP is found to significantly reduce the amount of NOx emission for both lean and rich premixed ammonia/air flames and the amount of NOx emission is well correlated with VAC⋅fAC⋅U0−1. The reduction of NOx emission through NH2 reactions is also identified by measuring NH2∗ chemiluminescence.