Dry low oxides of nitrogen lean premix module for industrial gas turbine

Abstract

The present invention relates generally to a lean premix module for an industrial gas turbine engine to satisfy increasingly stringent environmental requirements. A combustion system of the present invention employs a lean premix technique to meet the engine operability requirements and high power emission targets without the use of combustor diluent injection or post combustor exhaust treatment. A lean premix combustion mode is utilized to minimize primary zone combustion temperatures and limit the oxides of nitrogen production during high power engine operation. In one form of the present invention, the lean premix combustion is carried out in an off centerline silo combustor having a plurality of lean premix modules positioned parallel within a common liner. The lean premix modules receive the air from the compressor into a radial swirler and the fuel is dispensed along the radial swirler in order to be premixed with the air. A nozzle having a converging-diverging section is utilized to accelerate the fluid flow in the converging portion to prevent flashback, and in the diverging portion to expand the fluid flow to induce a centrally located recirculation zone. In another form of the present invention, the lean premix module is located inline in a can-annular combustion system.