摘要 |
<p>A gas turbine combustor comprises a cylindrical outer casing having one end closed by a header plate. A combustor liner provided with an inner combustion chamber which is divided into a first-stage combustion region on a side of the header plate and a second-stage combustion region formed on a downstream side of the first-stage combustion region. A first-stage fuel supply unit mounted to the header plate for injecting a first-stage fuel to the first-stage combustion region and a second-stage fuel supply unit mounted to the header plate for injecting a second-stage fuel previously mixed in a lean fuel state. The first-stage fuel supply unit includes a first-stage fuel nozzle assembly, which supplies the first-stage fuel, formed by combining a diffusion combustion nozzle and a pre-mixture combustion nozzle. The pre-mixture combustion nozzle has, at an intermediate portion thereof, a pre-mixing portion for preliminarily mixing the first-stage fuel with an air, and the pre-mixing portion having a diameter in a downstream portion thereof smaller than that of an upstream portion thereof so as to form a pre-mixed flow into a contraction flow. The pre-mixing fuel nozzle of the first stage fuel nozzle assembly is disposed so as to surround the diffusion combustion nozzle disposed in a central portion thereof.</p> |