Effect of swirl field on the fuel concentration distribution and combustion characteristics in gas turbine combustor with cavity

Abstract

The development of modern energy technology made more demands for the performance of the gas turbine, and more attention was paid to the engine's stability, efficiency and cleanliness. The technical level of combustor played an important role in the engine's efficiency and emissions issues. In order to broaden the stable working range and reduce emissions of the combustor, the fuel concentration distribution and combustion characteristics of trapped vortex combustor was numerically and experimentally analyzed in this study. The influences of swirl field and fuel injection mode were studied, and the research was conducted under the non-reaction condition and the reaction condition, respectively. Based on the numerical simulation results of fuel concentration distribution, a new type of trapped vortex combustor with centrifugal nozzles was designed, and the combustion characteristics of the combustor were experimentally evaluated. The results showed that a vertical double vortex structure could be formed in the cavity under various conditions. The air velocity of cavity inlet, the spray cone angle, and Sauter mean diameter of kerosene droplets had different effects on the liquid and gaseous fuel concentrations. High efficiency and low emissions combustion could be achieved, which was beneficial to improve gas turbine efficiency and reduce pollution emissions.