The Role of the Interactions Between the Primary Jets and the Recirculation Zone of a Model Gas Turbine Combustor on Pollutant Emissions

Abstract

The present work investigates the effect of utilizing transverse air jets as well as its interactions with the recirculation zone on pollutant emission characteristics at different jet locations, jet mass ratios, and overall equivalence ratio. A multiple gas analyzer based on Fourier transform infrared (FTIR) spectroscopy is employed to measure emissions concentrations generated during combustion of Jet-A fuel in a swirl-cup assembly. The goal of this study is to provide more insight into nitric oxides and carbon monoxide production within the primary zone of a highly swirling combustion and methods to reduce its formation. The results reveal the possibility of injecting air into the recirculation zone without altering the flame stability. Besides, depending on the jet location and strength, nitric oxides as well as carbon monoxide can be reduced simultaneously. Placing the primary air jet just downstream of the rich fuel recirculation zone can lead to 40% reduction in both nitric oxides and carbon monoxide. While in the case of recirculation zones in the lean side of stoichiometry, reduction of nitric oxides can occur if the air jets are placed just 1 inch above the swirler exit.