Biparametric assessment of the combustion stability in an industrial gas turbine combustor

2016 ◽  
Vol 30 (2) ◽  
pp. 879-887
Author(s):  
Won Joon Song ◽  
Dong-Jin Cha
Keyword(s):  
Gas Turbine ◽  
Combustion Stability ◽  
Gas Turbine Combustor ◽  
Industrial Gas Turbine

Predicting Thermoacoustic Instability in an Industrial Gas Turbine Combustor: Combining a Low Order Network Model With Flame LES

2017 ◽  
Author(s):  
Y. Xia ◽  
A. S. Morgans ◽  
W. P. Jones ◽  
J. Rogerson ◽  
G. Bulat ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Acoustic Waves ◽  
Gas Turbine Combustor ◽  
Network Modelling ◽  
Weakly Nonlinear ◽  
Thermoacoustic Instability ◽  
Reduced Chemistry ◽  
Flame Describing Function ◽  
Industrial Gas Turbine ◽  
Low Order

The thermoacoustic modes of a full scale industrial gas turbine combustor have been predicted numerically. The predictive approach combines low order network modelling of the acoustic waves in a simplified geometry, with a weakly nonlinear flame describing function, obtained from incompressible large eddy simulations of the flame region under upstream forced velocity perturbations, incorporating reduced chemistry mechanisms. Two incompressible solvers, each employing different numbers of reduced chemistry mechanism steps, are used to simulate the turbulent reacting flowfield to predict the flame describing functions. The predictions differ slightly between reduced chemistry approximations, indicating the need for more involved chemistry. These are then incorporated into a low order thermoacoustic solver to predict thermoacoustic modes. For the combustor operating at two different pressures, most thermoacoustic modes are predicted to be stable, in agreement with the experiments. The predicted modal frequencies are in good agreement with the measurements, although some mismatches in the predicted modal growth rates and hence modal stabilities are observed. Overall, these findings lend confidence in this coupled approach for real industrial gas turbine combustors.

Experimental Assessment of the Emissions Benefits of a Ceramic Gas Turbine Combustor

1996 ◽  
Author(s):  
K. O. Smith ◽  
A. Fahme
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Flow Distribution ◽  
Operating Conditions ◽  
Nox Emissions ◽  
Fuel Injector ◽  
Gas Turbine Combustor ◽  
Experimental Assessment ◽  
Industrial Gas Turbine ◽  
Combustor Liner

Three subscale, cylindrical combustors were rig tested on natural gas at typical industrial gas turbine operating conditions. The intent of the testing was to determine the effect of combustor liner cooling on NOx and CO emissions. In order of decreasing liner cooling, a metal louvre-cooled combustor, a metal effusion-cooled combustor, and a backside-cooled ceramic (CFCC) combustor were evaluated. The three combustors were tested using the same lean-premixed fuel injector. Testing showed that reduced liner cooling produced lower CO emissions as reaction quenching near the liner wall was reduced. A reduction in CO emissions allows a reoptimization of the combustor air flow distribution to yield lower NOx emissions.

Investigation on flame characteristics of industrial gas turbine combustor with different mixing uniformities

Fuel ◽  
2020 ◽  
Vol 259 ◽  
pp. 116297 ◽  
Author(s):  
Zhihao Zhang ◽  
Xiao Liu ◽  
Yaozhen Gong ◽  
Zhiming Li ◽  
Jialong Yang ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Gas Turbine Combustor ◽  
Industrial Gas Turbine

Modeling a Non-Premixed Industrial Gas Turbine Combustor by a Transported PDF Approach With ILDM Chemistry

2007 ◽  
Author(s):  
Sebastian Harder ◽  
Franz Joos
Keyword(s):  
Gas Turbine ◽  
Particle System ◽  
Measurement Techniques ◽  
Combustion Process ◽  
Generic Model ◽  
Numerical Comparison ◽  
Gas Turbine Combustor ◽  
Turbulent Diffusion Flame ◽  
Pdf Methods ◽  
Industrial Gas Turbine

The combustion process in a typical can combustor of an industrial gas turbine is determined by the nature of turbulent flow, the chemical reaction and the interaction with each other. Turbulent non-premixed combustion can be divided into different flame regimes in terms of time- and length scales. A typical non-premixed turbulent diffusion flame in a gas turbine combustor covers all regimes. PDF methods are suitable to describe the entire combustion regime without any limitation to a certain regime. In this paper a hybrid pdf/RANS method is presented. The pdf model is based on the transported composition pdf equation, coupled with a commercial three dimensional CFD solver. A stochastic particle system in a Lagrangian framework is used to solve the pdf equation. The chemistry is described by an ILDM approach. The numerical results have been validated with measurements. The test rig consists of an non-premixed gas turbine can combustor with a typical primary and secondary zone. A main air swirler stabilizes the natural gas/air mixture in the primary zone, followed by a burnout and a mixing zone. The setup is investigated using conventional measurement techniques. Field measurements of compositions and mixture fraction as well as temperature are compared with the pdf/RANS calculations. The benefit of this approach is a realistic prediction of all relevant species. The complete one point statistics of the numerical calculations are used to identify the different combustion regimes from the combustor to the exit. The numerical comparison of pdf-, edm- and flamelet-model shows that the pdf approach can be used to describe a realistic gas turbine combustor. In the past, pdf-methods were applied only on simple generic model flames. The purpose of the presented paper is to demonstrate the application of a transported-pdf approach to a realistic gas turbine combustor.

Study of Flame Stability in a Step Swirl Combustor

1996 ◽  
Vol 118 (2) ◽  
pp. 308-315 ◽  
Author(s):  
M. D. Durbin ◽  
M. D. Vangsness ◽  
D. R. Ballal ◽  
V. R. Katta
Keyword(s):  
Gas Turbine ◽  
Recirculation Zone ◽  
Swirling Flow ◽  
Tangential Velocity ◽  
Combustion Stability ◽  
Combustion Model ◽  
Fuel Injector ◽  
Gas Turbine Combustor ◽  
Swirl Combustor ◽  
Radial Profiles

A prime requirement in the design of a modern gas turbine combustor is good combustion stability, especially near lean blowout (LBO), to ensure an adequate stability margin. For an aeroengine, combustor blow-off limits are encountered during low engine speeds at high altitudes over a range of flight Mach numbers. For an industrial combustor, requirements of ultralow NOx emissions coupled with high combustion efficiency demand operation at or close to LBO. In this investigation, a step swirl combustor (SSC) was designed to reproduce the swirling flow pattern present in the vicinity of the fuel injector located in the primary zone of a gas turbine combustor. Different flame shapes, structure, and location were observed and detailed experimental measurements and numerical computations were performed. It was found that certain combinations of outer and inner swirling air flows produce multiple attached flames, aflame with a single attached structure just above the fuel injection tube, and finally for higher inner swirl velocity, the flame lifts from the fuel tube and is stabilized by the inner recirculation zone. The observed difference in LBO between co- and counterswirl configurations is primarily a function of how the flame stabilizes, i.e., attached versus lifted. A turbulent combustion model correctly predicts the attached flame location(s), development of inner recirculation zone, a dimple-shaped flame structure, the flame lift-off height, and radial profiles of mean temperature, axial velocity, and tangential velocity at different axial locations. Finally, the significance and applications of anchored and lifted flames to combustor stability and LBO in practical gas turbine combustors are discussed.

Droplet Burning and Evaporation Times for Distillate and Residual Fuel Oils

1980 ◽  
Author(s):  
P. C. T. de Boer
Keyword(s):  
Gas Turbine ◽  
Constant Velocity ◽  
Droplet Diameter ◽  
Diffusion Constant ◽  
Gas Mixture ◽  
Residual Oil ◽  
Gas Turbine Combustor ◽  
Initial Droplet ◽  
Fuel Oils ◽  
Industrial Gas Turbine

Estimates are given of the burning and evaporation times of No. 2 distillate and No. 6 residual oil droplets, under conditions typical of industrial gas turbine combustors. Account is taken of the temperature dependence of the specific heat, the diffusion constant, and the thermal conductivity of the gas mixture surrounding the droplet. Detailed calculations are presented of the factor by which the droplet lifetime is reduced as a result of convection, for the case that the droplet is released in a gas moving at constant velocity. This factor is on the order of four for the conditions of interest. Using estimates of initial droplet diameter based on data reported by Jasuja, it is found that the ratio of characteristic droplet burning time to characteristic droplet residence time in a typical industrial gas turbine combustor is much smaller than 1 for distillate oil, but may be on the order of 1 for residual oil.

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