Investigation of Reverse Flow Slinger Combustor With Jet A-1 and Methanol

Abstract

This paper describes an experimental investigation of the reverse flow slinger (RFS) combustor that has been developed in order to attain high flame stability and low emissions in gas turbine (GT) engines. The combustor employs centrifugal fuel injection through a rotary atomizer and performs flame stabilization at the stagnation zone generated by reverse flow configuration. The design facilitates entrainment of hot product gases and internal preheating of inlet air, which enhances flame stability and permits stable lean operation for low NOx. Moreover, a rotary atomizer eliminates the need for high injection pressures, resulting in a compact and lightweight design. Atmospheric pressure combustion was performed with liquid fuels, Jet A-1 and methanol, at ultralean fuel–air ratios (FARs) with thermal intensity varying from 30 to 52 MW/m3 atm. Combustor performance was evaluated by analyzing the lean blowout, emissions, and combustion efficiency. A very low lean blowout corresponding to global equivalence ratio of 0.1 was observed, which showed the combustor's high flame stability. Sustained and stable combustion at low heat release was attained, and NOx emissions as low as 0.4 g/kg and 0.1 g/kg were achieved with Jet A-1 and methanol, respectively. Combustion efficiency of around 55% and 90% was obtained in operation with Jet A-1 and methanol. The overall combustor performance was significantly better with methanol in terms of emissions and efficiency.