Industrial RB211 DLE Gas Turbine Combustion Update

Abstract

Industrial gas turbines have universally had problems with combustion amplified pressure oscillations (combustion instability or noise) in premix lean burn combustors. Reference 1 issued by General Electric is a particularly good report. Under specific conditions a resonant frequency achieves sufficient amplitude to cause severe damage to the combustor. As the emissions are reduced to lower levels, by achieving better uniformity of fuel and air distribution and a larger percentage of the air is used in the combustion process, then these amplitudes have the potential to become greater especially at high pressure ratios. Small changes in either ambient conditions or fuel quality appear to cause noise amplitudes to become unacceptable.