Abstract
Syngas spark ignition experiments were conducted using a single nozzle model combustor under typical gas turbine startup conditions. Ignition performance was characterized by measuring lean ignition limits. Effects of fuel composition (H2, CO2, and N2) and inlet air flow velocity on ignition performance were investigated. Results show that H2 content and air flow velocity both have a strong impact on ignition performance. A small amount of H2 can significantly improve the ignition performance of syngas. Data analysis indicates that chemical time, rather than ignition delay time, is more suited for characterizing the reactivity of syngas influencing spark ignition performance. Effects of fuel composition and air flow velocity can be captured by a Damköhler number–flame temperature correlation. A 3-step ignition theory is proposed to explain the correlation. Compared to natural gas, syngas has a better ignition performance due to the presence of H2. Considering that gas turbines operating on syngas still have to start with natural gas or diesel, this study demonstrates that syngas is a promising ignition fuel for gas turbine startup.