Forced Oscillation Characteristics of Natural Gas Mixed with Hydrogen Combustion in Gas Turbine Central Staged Burner

Abstract

Natural gas mixed with hydrogen combustion is one of the important measures to reduce carbon emissions of gas turbine. However, the composition change of fuel will lead to changes in the flame structure and combustion stability of the combustor. In order to analyze the combustion instability of natural gas mixed with hydrogen combustion in the central staged burner, the effects of different hydrogen doping ratios on the transient flame structure, pressure and heat release response of the central staged combustion are experimentally studied. The proper orthogonal decomposition (POD) method is used to extract the characteristic modes of flame pulsation. It is found that the flame pulsation mainly includes two modes: a strong pulsation in the interference zone of flame and an axial disturbance. The experimental results show that as the volume ratio of hydrogen doped increases from 0% to 30%, the flame front moves upstream, the spacing between two staged flames is shortened, the energy proportion of pulsation mode corresponding to the flame interference increases, and the coupling of pressure and heat release is strengthened, which ultimately results in a 9% increase in pressure response and a 37% increase in heat release response in the combustor.

Keywords

• central staged burner
• natural gas mixed with hydrogen
• forced oscillation
• proper orthogonal decomposition (pod)