A Numerical Evaluation of Different Oxy-Fuel Concepts for a Gas Turbine Combustor

Abstract

In the present study, a numerical evaluation of different oxy-fuel concepts for a typical gas turbine combustor is performed to investigate how the inlet conditions affect fuel and CO burnout, NOx and soot emissions, and wall heat fluxes. Three oxy-fuel cases with different distribution of oxygen to the inlets are compared with a reference case using air as an oxidiser. Three-dimensional numerical simulations are performed using the in-house CFD code SPIDER. Turbulent combustion is modelled by the Eddy Dissipation Concept (EDC) with detailed chemistry and soot formation reactions. Whereas low oxygen concentrations at the fuel inlet lead to extinction of the flame, the temperature in the primary combustion zone becomes very high leading to unacceptable wall heat fluxes at high oxygen concentrations. NOx, hydrocarbons and soot emissions are very low while CO emissions are relatively high for the oxy-fuel cases.