Burner, combustor, and gas turbine

Abstract

The present invention provides a burner, a combustor equipped with the burner, and a gas turbine, with which it is possible to premix a first hydrocarbon-based fuel (for example, natural gas), a second fuel (for example, hydrogen gas), and combustion air, and to spray into the combustion chamber of the combustor a thin and uniform concentration distribution of the premixed air, and with which it is possible to suppress the amount of NOx discharged. On the upstream side of the premix flow path, hydrogen gas is sprayed from second fuel spray nozzles, which project into the premix flow path, into the flow of the combustion air flowing toward the center from the outer edge of an outer cylinder, whereby a primary air-fuel mixture having a uniform concentration distribution is generated without affecting a low-speed region of the combustion air. Natural gas is then sprayed from first fuel spray nozzles into the primary air-fuel mixture, whereby the natural gas, which has a high specific gravity, and the primary air-fuel mixture are adequately mixed in a stirring fashion, and a secondary air-fuel mixture (premixed air) is generated that is lean and has a more uniform concentration distribution than the first air-fuel mixture. By combusting this type of premixed air in the combustion chamber, NOx in the combustion exhaust gas can be suppressed.