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The Effect of the Degree of Premixedness on Self-Excited Combustion Instability

Journal Article · · Journal of Engineering for Gas Turbines and Power
DOI:https://doi.org/10.1115/1.4049486· OSTI ID:1780831
 [1];  [2];  [2];  [2]
  1. Pennsylvania State Univ., University Park, PA (United States); Pennsylvania State University
  2. Pennsylvania State Univ., University Park, PA (United States)
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The use of lean, premixed fuel and air mixtures is a common strategy to reduce NOx emissions in gas turbine combustors. However, this strategy causes an increased susceptibility to self-excited instability, which manifests as fluctuations in heat release rate, flow velocity, and combustor acoustics that oscillate in-phase in a feedback loop. Here, this study considers the effect of the level of premixedness on the self-excited instability in a single-nozzle combustor. In this system, the fuel can be injected inside the nozzle to create a partially-premixed mixture or far upstream to create a fully-premixed mixture, varying the level of premixedness of the fuel and air entering the combustor. When global equivalence ratio is held constant, the cases with higher levels of premixing have higher instability amplitudes. High-speed CH* chemiluminescence imaging shows that the flame for these cases is more compact and the distribution of the heat release rate oscillations is more concentrated near the corner of the combustor in the outer recirculation zones. Rayleigh index images, which are a metric for the relative phase of pressure and heat release rate oscillations, suggest that vortex rollup in the corner region is primarily responsible for determining instability characteristics when premixedness is varied. This finding is further supported through analysis of local flame edge dynamics.
Research Organization:
Pennsylvania State Univ., University Park, PA (United States)
Sponsoring Organization:
USDOE Office of Fossil Energy (FE)
Grant/Contract Number:
FE0025495
OSTI ID:
1780831
Journal Information:
Journal of Engineering for Gas Turbines and Power, Journal Name: Journal of Engineering for Gas Turbines and Power Journal Issue: 7 Vol. 143; ISSN 0742-4795
Publisher:
ASMECopyright Statement
Country of Publication:
United States
Language:
English

References (20)

The role of equivalence ratio oscillations in driving combustion instabilities in low NOx gas turbines journal January 1998
Bifurcation of flame structure in a lean-premixed swirl-stabilized combustor: transition from stable to unstable flame journal February 2004
The combined dynamics of swirler and turbulent premixed swirling flames journal September 2010
Cinematographic OH-PLIF measurements of two interacting turbulent premixed flames with and without acoustic forcing journal March 2012
Flame dynamics of a variable swirl number system and instability control journal September 2013
The effect of variable fuel staging transients on self-excited instabilities in a multiple-nozzle combustor journal August 2018
Dynamics of acoustically forced non-premixed flames close to blow-off journal July 2018
Flame sheet dynamics of bluff-body stabilized flames during longitudinal acoustic forcing journal January 2009
Investigation of azimuthal staging concepts in annular gas turbines journal October 2011
Tomographic reconstruction of OH* chemiluminescence in two interacting turbulent flames journal December 2012
Azimuthal instabilities in annular combustors: standing and spinning modes journal September 2013
A Mechanism of Combustion Instability in Lean Premixed Gas Turbine Combustors journal April 2000
Influence of the Combustor Aerodynamics on Combustion Instabilities From Equivalence Ratio Fluctuations journal December 2002
Comparison of the Flow Field of a Swirl Stabilized Premixed Burner in an Annular and a Single Burner Combustion Chamber journal April 2010
Three-Dimensional Chemiluminescence Imaging of Unforced and Forced Swirl-Stabilized Flames in a Lean Premixed Multi-Nozzle Can Combustor journal September 2013
The Effect of Fuel Staging on the Structure and Instability Characteristics of Swirl-Stabilized Flames in a Lean Premixed Multinozzle Can Combustor journal August 2017
Dynamics of a Longitudinally Forced, Bluff Body Stabilized Flame journal January 2011
Comparison of Single- and Multinozzle Reacting Swirl Flow Dynamics journal March 2018
Experimental Investigation of Limit-Cycle Oscillations in an Unstable Gas Turbine Combustor journal January 2002
Combustion Dynamics and Instabilities: Elementary Coupling and Driving Mechanisms journal September 2003

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