Combustion instability characteristics of H 2 /CO/CH 4 syngases and synthetic natural gases in a partially-premixed gas turbine combustor: Part II—Time lag analysis

The scale-resolving simulation of a practical gas turbine combustor is performed using a partially premixed finite-rate chemistry combustion model. The combustion model assumes finite-rate chemistry by limiting the chemical reaction rate with flame speed. A comparison of the numerical results with the experimental temperature and species mole fraction clearly showed the superiority of the shear stress transport, K-omega, scale adaptive turbulence model (SSTKWSAS). The model outperforms large eddy simulation (LES) in the primary region of the combustor, probably for two reasons. First, the lower amount of mesh employed in the simulation for the industrial-size combustor does not fit the LES’s explicit mesh size dependency requirement, while it is sufficient for the SSTKWSAS simulation. Second, coupling the finite-rate chemistry method with the SSTKWSAS model provides a more reasonable rate of chemical reaction than that predicted by the fast chemistry method used in LES simulation. Other than comparing with the LES data available in the literature, the SSTKWSAS-predicted result is also compared comprehensively with that obtained from the model based on the unsteady Reynolds-averaged Navier–Stokes (URANS) simulation approach. The superiority of the SSTKWSAS model in resolving large eddies is highlighted. Overall, the present study emphasizes the effectiveness and efficiency of coupling a partially premixed combustion model with a scale-resolving simulation method in predicting a swirl-stabilized, multi-jets turbulent flame in a practical, complex gas turbine combustor configuration.

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Numerical analysis of the effect of the hydrogen composition on a partially premixed gas turbine combustor

International Journal of Hydrogen Energy ◽

10.1016/j.ijhydene.2019.01.066 ◽

2019 ◽

Vol 44 (12) ◽

pp. 6278-6286 ◽

Cited By ~ 5

Author(s):

Jaehyun Nam ◽

Younghun Lee ◽

Seongpil Joo ◽

Youngbin Yoon ◽

Jack J. Yoh

Keyword(s):

Numerical Analysis ◽

Gas Turbine ◽

Gas Turbine Combustor ◽

Partially Premixed

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The Effect of Fuel Composition on Combustion Instability Mode Occurrence in a Model Gas Turbine Combustor

Volume 4A: Combustion, Fuels and Emissions ◽

10.1115/gt2015-42601 ◽

2015 ◽

Cited By ~ 2

Author(s):

Jisu Yoon ◽

Seongpil Joo ◽

Min Chul Lee ◽

Jeongjin Kim ◽

Jaeyo Oh ◽

...

Keyword(s):

Gas Turbine ◽

Alternative Fuels ◽

Combustion Instability ◽

Longitudinal Mode ◽

Fuel Composition ◽

Instability Mode ◽

Gas Turbine Combustor ◽

Global Issues ◽

Model Gas Turbine Combustor ◽

Instability Frequency

Recently, energy resource depletion and unstable energy prices have become global issues. Worldwide pressure to secure and make more gas and oil available to support global power needs has increased. To meet these needs, alternative fuels composed of various types of fuels have received attention, including biomass, dimethyl ether (DME), and low rank coal. For this reason, the fuel flexibility of the combustion system becomes more important. In this study, H2 and CH4 were selected as the main fuel composition variables and the OH-chemiluminescence measurement technique was also applied. This experimental study was conducted under equivalence ratio and fuel composition variations with a model gas turbine combustor to examine the relation between combustion instability and fuel composition. The combustion instability peak occurs in the H2/CH4 50:50 composed fuel and the combustion instability frequency shifted to higher harmonic of longitudinal mode based on the H2 concentration of the fuel. Based on instability mode and flame length calculation, the effect of the convection time during the instability frequency increasing phenomenon was found in a partially premixed gas turbine combustor. The time-lag analysis showed that the short convection time in a high H2 concentration fuel affects the feedback loop period reduction and, in these conditions, high harmonics of longitudinal mode instability occurs. This fundamental study on combustion instability frequency shifting characteristics was conducted for H2/CH4 composed fuel and the results contribute key information for the conceptual design of a fuel flexible gas turbine and its optimum operation conditions.

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Effects of superheated steam on combustion instability and NOx emissions in a model lean premixed gas turbine combustor

Fuel ◽

10.1016/j.fuel.2020.119646 ◽

2021 ◽

Vol 288 ◽

pp. 119646

Author(s):

Chengfei Tao ◽

Hao Zhou

Keyword(s):

Gas Turbine ◽

Superheated Steam ◽

Combustion Instability ◽

Nox Emissions ◽

Gas Turbine Combustor ◽

Lean Premixed

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Thermoacoustic Modeling of a Gas Turbine Combustor Equipped With Acoustic Dampers

Journal of Turbomachinery ◽

10.1115/1.1791284 ◽

2005 ◽

Vol 127 (2) ◽

pp. 372-379 ◽

Cited By ~ 39

Author(s):

Valter Bellucci ◽

Bruno Schuermans ◽

Dariusz Nowak ◽

Peter Flohr ◽

Christian Oliver Paschereit

Keyword(s):

Transfer Function ◽

Gas Turbine ◽

Mixture Fraction ◽

Time Lag ◽

Multiple Input Multiple Output ◽

Three Dimensional ◽

Analytical Models ◽

Gas Turbine Combustor ◽

Input Multiple Output ◽

The Time Domain

In this work, the TA3 thermoacoustic network is presented and used to simulate acoustic pulsations occurring in a heavy-duty ALSTOM gas turbine. In our approach, the combustion system is represented as a network of acoustic elements corresponding to hood, burners, flames and combustor. The multi-burner arrangement is modeled by describing the hood and combustor as Multiple Input Multiple Output (MIMO) acoustic elements. The MIMO transfer function (linking acoustic pressures and acoustic velocities at burner locations) is obtained by a three-dimensional modal analysis performed with a Finite Element Method. Burner and flame analytical models are fitted to transfer function measurements. In particular, the flame transfer function model is based on the time-lag concept, where the phase shift between heat release and acoustic pressure depends on the time necessary for the mixture fraction (formed at the injector location) to be convected to the flame. By using a state-space approach, the time domain solution of the acoustic field is obtained. The nonlinearity limiting the pulsation amplitude growth is provided by a fuel saturation term. Furthermore, Helmholtz dampers applied to the gas turbine combustor are acoustically modeled and included in the TA3 model. Finally, the predicted noise reduction is compared to that achieved in the engine.

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