Investigation of Combustion Instabilities using a Premixed Combustion Chamber Test Rig with a Matrix Burner



In today's gas turbines for stationary applications, a premixed fuel / air mixture is fed to the combustion chamber for efficiency and emission reasons, which is then burned under lean conditions. In operating ranges close to the lean extinguishing limit, small disturbances can cause extinguishing and an oscillating flames. The interaction of heat release and acoustic sound field within the combustion chamber can result in so-called thermoacoustically induced pressure oscillations, which vibrate to such an extent that the mechanical component integrity is compromised and the combustion process is disturbed.
The aim of this research project is to identify the mechanisms leading to these instable system conditions at an institute's premixed combustion chamber test facility (power Pth <100 KW) and to develop measures, which are able to influence the system with regard to the thermoacoustically induced combustion instabilities.
The effects on the emission behavior of gas turbine combustion chambers as a function of parameters which characterize instable combustion states are also investigated.



Experimental detection of characteristic variables for the identification of thermo-acoustically induced combustion instabilities: sound pressure amplitude measurement, FFT analysis, temperature and pressure measurement, exhaust gas analysis, chemiluminescence measurements, PIV, LDA, 1D modeling approaches.



Frank Weidner, Manfred Wirsum
Analysis of Combustion Instabilities in a Matrix Burner Test Rig with Premixed Methane-/Air-Combustion
15th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery, Feb. 24-28, 2014, , Honolulu, Hawaii, USA