Development of a High Pressure Combustion Simulator to Study Combustion Instability Control Methods and Strategies

Abstract Gas turbine combustors employing lean premixed combustion are prone to combustion instability. Combustion instability, if unchecked, will have deleterious effects to the combustor and hence needs to be controlled. Active control methods are preferred to obtain better off-design performance. The effectiveness of active control methods is dependent on the quality of controller which in-turn depends on the quality of model. In the present work, an input-output model structure, where the output of the system at the current instant is modelled as a nonlinear function of delayed inputs and outputs is chosen. As there are infinite possibilities for representation of nonlinear functions, all parameters in the model structure like time delay between input and output, number of delayed input and output terms and the appropriate form of nonlinear function can be obtained only iteratively. However, prior knowledge of delay and number of delayed inputs and outputs reduces the computational intensity. To this end, the present work utilizes the method of Lipschitz indices to obtain the number of delayed inputs and outputs.

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Combustion Instability Control Through Acoustic Modulation at the Inlet Boundary: Experiments

Journal of Propulsion and Power ◽

10.2514/1.b35649 ◽

2015 ◽

Vol 31 (6) ◽

pp. 1672-1688 ◽

Cited By ~ 3

Author(s):

John W. Bennewitz ◽

Robert A. Frederick ◽

Jacob T. Cranford ◽

David M. Lineberry

Keyword(s):

Combustion Instability ◽

Instability Control ◽

Acoustic Modulation

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Forced Nonlinear Acoustic Damping in a Rijke Tube and its Application to Combustion Instability Control

50th AIAA/ASME/SAE/ASEE Joint Propulsion Conference ◽

10.2514/6.2014-3486 ◽

2014 ◽

Cited By ~ 1

Author(s):

Eric J. Jacob

Keyword(s):

Combustion Instability ◽

Rijke Tube ◽

Acoustic Damping ◽

Instability Control ◽

Nonlinear Acoustic

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Application of Active Combustion Instability Control to a Heavy Duty Gas Turbine

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.2818459 ◽

1998 ◽

Vol 120 (4) ◽

pp. 721-726 ◽

Cited By ~ 80

Author(s):

J. R. Seume ◽

N. Vortmeyer ◽

W. Krause ◽

J. Hermann ◽

C.-C. Hantschk ◽

...

Keyword(s):

Gas Turbine ◽

Gas Turbines ◽

Combustion Instability ◽

Pressure Fluctuations ◽

Preventive Measure ◽

Feedback System ◽

Operating Conditions ◽

Combustion Instabilities ◽

Instability Control ◽

Heavy Duty Gas Turbine

During the prototype shop tests, the Model V84.3A ring combustor gas turbine unexpectedly exhibited a noticeable “humming” caused by self-excited flame vibrations in the combustion chamber for certain operating conditions. The amplitudes of the pressure fluctuations in the combustor were unusually high when compared to the previous experience with silo combustor machines. As part of the optimization program, the humming was investigated and analyzed. To date, combustion instabilities in real, complex combustors cannot be predicted analytically during the design phase. Therefore, and as a preventive measure against future surprises by “humming,” a feedback system was developed which counteracts combustion instabilities by modulation of the fuel flow rate with rapid valves (active instability control, AIC). The AIC achieved a reduction of combustion-induced pressure amplitudes by 86 percent. The Combustion instability in the Model V84.3A gas turbine was eliminated by changes of the combustor design. Therefore, the AIC is not required for the operation of customer gas turbines.

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