Investigations of the Stabilities of Piloted Flames Using Blast Furnace Gas

The effective utilization of low-grade energy sources generated from steel-making processes provides not only excellent opportunities for low cost power generation but also a significant means for the reduction of greenhouse gas emissions. In this paper, the work was carried out to study the static and dynamic combustion instabilities for gas turbine combustors burning low-calorific-value blast furnace gas (BFG). A burner was designed to stabilize the BFG flame with central pilot flames. A diagnostic system was set up to detect the characteristics of flame dynamics. In the experiments, the fuel ratio between the pilot and main burner and, the equivalence ratio of the main flame and the annular flow velocity were varied for the investigation of the combustion lean blowout (LBO) limits. The flame dynamics near LBO were investigated. The dynamic responses of the flame to flow perturbations were also measured. A network model was employed to study and validate the blowout mechanisms. The LBO limits were calculated and compared with experimental results for various equivalence ratios.Copyright © 2015 by ASME