Comparison of center nozzle staging to outer nozzle staging in a multi-flame combustor

Conference · Mon Jun 11 04:00:00 EDT 2018 · Proceedings of ASME Turbo Expo 2018

DOI:https://doi.org/10.1115/GT2018-75423· OSTI ID:1462986

Culler, Wyatt ^[1]; Chen, Xiaoling; Peluso, Stephen; Santavicca, Domenic; O'Connor, Jacqueline

---

1. Pennsylvania State University

Combustion instability in gas turbines is often mitigated using fuel staging, a strategy where the fuel is split unevenly between different nozzles of a multiple-nozzle combustor. This work examines the efficacy of different fuel staging configurations by comparing axisymmetric and non-axisymmetric fuel staging in a four-around-one model gas turbine combustor. Fuel staging is accomplished by increasing the equivalence ratio of the center nozzle (axisymmetric staging) or an outer nozzle (nonaxisymmetric staging). When the global equivalence ratio is ϕ = 0:70 and all nozzles are fueled equally, the combustor undergoes longitudinal, self-excited oscillations. These oscillations are suppressed when the center nozzle equivalence ratio is increased above ϕ_Staging = 0.79. This bifurcation equivalence ratio varies between ϕ_Staging = 0.86 and ϕ_Staging = 0.76 for the outer nozzles, and is attributed to minor hardware differences between each nozzle. High speed CH* chemiluminescence images in combination with dynamic pressure measurements are used to determine the instantaneous phase difference between the heat release rate fluctuation and the combustor pressure fluctuation throughout the combustor. This analysis shows that the staged flame has similar phase relationships for all staging configurations. It is found that axisymmetric staging can be as effective as nonaxisymmetric staging; however, the aforementioned hardware variations can impact both the bifurcation equivalence ratio and the effectiveness of staging.

• Research Organization: Pennsylvania State University
• Sponsoring Organization: USDOE Office of Fossil Energy (FE)
• DOE Contract Number: FE0025495
• OSTI ID: 1462986
• Conference Information: Journal Name: Proceedings of ASME Turbo Expo 2018
• Country of Publication: United States
• Language: English

Related Subjects

20 FOSSIL-FUELED POWER PLANTS
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS