Combustor for gas turbine

Abstract

A gas turbine combustor comprises an inner cylinder provided with louvers in an outer periphery thereof, defines a head combustion chamber and a main combustion chamber located downstream of and greater in diameter than the head combustion. An outer cylinder surrounds the inner cylinder and defines an air passage therebetween. A first burner communicates with the head combustion chamber and supplies air with gaseous fuel, and a second burner being disposed in the air passage near the head combustion chamber and supplying air and gaseous fuel into the main combustion chamber. The second burner is formed with a plurality of air inlets by a plurality of vanes which are disposed in an annular passage and which swirl the air, and with gaseous fuel jet ports near the inner peripheries of the air inlets. When the flow rate of the supplied fuel is small, the fuel flows along an inner-peripheral surface of the second burner, and when the flow rate is large, the fuel from the air inlets moves from the inner-peripheral surface toward the outer-peripheral surface of the second burner so as to be mixed well with the air supplied into the main combustion chamber. Thus, the production of NO.sub.x, CO, HC etc. can be decreased over the whole operating range of the turbine.