Computational Studies of the Operating Conditions of a Combustor with Staged Combustion of Fuel-Air Mixture

The paper is devoted to the computational studies of the combustion chamber (CC) with staged combustion of fuel-air mixture for a high-temperature gas-turbine unit (GTU) with a working medium temperature of up to 1670°C. The analyzed combustion chamber is equipped with two burning devices (BD) arranged in series (BD1 and BD2) and three independent fuel supply channels connected to a pilot (diffusion) burner of BD1 and pre-mixing burners of BD1 and BD2. The paper presents the results of calculating the most thermally stressed operating parameters of the combustion chamber with the outlet temperature of up to 1670°C, and shows how the fuel distribution between the CC zones affects the non-uniformity of the temperature and concentration profiles of harmful emissions at the CC outlet at various fuel distribution ratios between the pre-mixing burners of BD1 and BD2. Based on the results of a series of calculations, an algorithm is proposed for controlling the GTU operation by re-distributing fuel between the fuel channels to minimize the level of harmful emissions.