Emission characteristics of turbulent premixed propane/air/carbon dioxide and propane/air/ammonia swirl flames through a rich‐lean combustor

Abstract

This study is dedicated to understanding the combustion characteristics of turbulent premixed C3H8‐Air‐CO2 and C3H8‐Air‐NH3 swirl flames in a rich‐lean combustor at atmospheric pressure. In this study, the emission characteristics of both flames were obtained through two‐dimensional numerical simulations based on the RANS approach with Realizable k‐ϵ turbulence model for turbulence closure, and the P1 radiation model for the flame radiation inside the combustor. The turbulence‐chemistry interaction was modeled using the Finite‐Rate Eddy Dissipation Model (FR/EDM) model with a reduced reaction mechanism (Jones‐Lindstedt). The study was conducted for five volumetric fractions of CO2 or NH3, XCO2/NH3 = 0,4%, 8%, 12%, 16%, two swirl numbers (Sn = 0.6 and 1.05), and four equivalence ratios, ϕ = 0.4 (with dilution), 0.5, 0.8, and 1. The results show that the addition of NH3 to C3H8‐Air flames promotes the production of CO, whereas the minimum NOx emission (0.14 ppm) was obtained for a dilution rate of 16% at ϕ = 0.8 and Sn = 0.6 corresponding to an outlet temperature of Tout = 1652 K.