Liquid petroleum gas flame in a double-swirl gas turbine model combustor: Lean blow-out, pollutant, preheating

Amir Mardani, Rezapour Rastaaghi, Fazlollahi Ghomshi
2020 Thermal Science  
In this paper, lean blow-out (LBO) limits in a double swirl gas turbine model combustor were investigated experimentally for Liquid Petroleum Gas (LPG) fuel. The LBO curve was extracted for different combustor configurations. While burner could operate reasonably under ultra-lean conditions, two different sets of operating conditions, one with a low flow rate (LFR) and another one with high flow rate (HFR), are identified and studied in terms of LBO and pollutant. Results showed that while the
more » ... lame structure was similar in both cases, the chamber responses to geometrical changes and also preheating are minimal at the LFR. That means confinement and injector type have desirable effects on stability borders but not for the LFR. The channeled injector shifted down the LBO limit around 28 percent at HFR. Measurements on the combustor exhaust gas composition and temperature indicate a region with relatively complete combustion and reasonable temperature and a very low level of exhaust NOx pollutants (i.e., below ten ppm) at about 25-50% above the LBO. In this operating envelope, a burner power increment led to a higher exhaust average temperature and combustion efficiency, while NOx formation decreased. Preheating the inlet air up to 100 o C results in an improvement in burner stability in about 10 percent, but NOx production intensifies more than three times. Results indicate that the LBO limit is configured more by the burner design and aerodynamic aspects rather than the fuel type.
doi:10.2298/tsci190623139m fatcat:c5swswjlyzcjxp2egactyhuveq