Development of Dry Two-Stage Low-NOx Combustor for a Gas Turbine

A dry two-stage low NOx combustor for a 73 MW gas turbine has been developed to meet stringent NOx limitations in Japan. This combustion system has a fuel-air control mechanism to ensure stable switching from one-stage combustion to two-stage combustion. NOx emission is very low not only at full load but also in the entire gas turbine operating range. The NOx characteristics have proved to be within the goal in full scale, full pressure combusion tests. This paper outlines the development plan and describes the structure and combustion characteristics of the low NOx combustor.