REFINING THE DESIGN OF A SECOND COMBUSTION ZONE BURNER DEVICE FOR A STAGED AIR-FUEL MIXTURE COMBUSTION CHAMBER FOR USE IN POTENTIAL GAS-TURBINE UNITS

摘要

The paper is devoted to studying the combustion of an air-fuel mixture (AFM) in the second zone of a gas turbine unit's (GTU) combustion chamber (CC) with staged AFM combustion and initial working medium temperature of about 1700℃. The staged AFM combustion scheme is an effective way to mitigate the NOx emission at high combustion product temperatures. This scheme involves two sequentially located inside the combustion chamber burner devices (BD) facilitating the AFM supply to the respective combustion zones of the chamber. The AFM distribution and concentration are determined based on minimizing the harmful emissions. The first burner device (BD1) is typical for the low-emission combustion chambers, and its design has been well-studied. BD1 consists of a pilot burner (PB) operating in the diffusion mode during startup, and main burner (MB) operating in the pre-mixing mode under the main loads. The paper discusses the design of the second zone burner device (BD2) providing a reliable and low-emission operation of the combustion chamber. The estimates are also provided to characterize the effect of non-uniformity of the concentration profile at the BD2 outlet on the formation of nitrous oxide emissions and temperature distribution throughout the volume of the combustion chamber.