Emission characteristics of a model combustor for aero gas turbine application

Abstract

A TeLESS concept combustor using lean staged NOx reduction technology has been proposed on the basis of previous studies. TeLESS means the Technology of Low Emissions of Stirred Swirl in this paper. As the power condition increases, the TeLESS combustor will work in low power mode, circumferentially staged mode, or high power mode. Meanwhile, each combustor dome is in either only pilot mode or two stages mode. Emission characteristics of TeLESS combustor have been investigated experimentally in a single-module rectangular model combustor. NOx emissions and combustion efficiency of the model combustor were measured under high pressures and temperatures up to 2.8MPa and 845K. Fuel stage ratio ranged from 1.5% to 34.9% in the tests. The fuel staging effects on NOx emissions, combustion efficiency and stability of the model combustor were studied under circumferentially-staged mode and high power mode conditions. Tests results showed that the optimal fuel stage ratio for the combustor varied with operating conditions. A new empirical NOx model, based on the idea of flame partition, was proposed for staged combustion. Combustor pressure, inlet temperature, and dome equivalence ratio, as well as the dome fuel stage ratio were used as input parameters in the NOx model. Finally, the empirical model was used to predict landing and take-off cycle NOx emissions for the TeLESS combustor.