Combustion Science and Technology, Vol.177, No.9, 1725-1745, 2005
Active optimization of the performance of a gas-turbine combustor
A model natural gas-fired gas-turbine combustor is utilized to evaluate active optimization strategies. Sensors for exhaust species and reaction zone chemiluminescence are utilized with an adaptive fuel injection strategy in a closed-loop feedback control system. The feedback sensors consist of (1) traditional extractive probe-based exhaust measurements of CO and NOX emissions and (2) chemiluminescence to provide very fast, yet accurate, indicators of performance. A direction-set algorithm is utilized to search for the region of optimal performance. The objectives of the study are to assess (1) the viability of controlling the spatial distribution for performance control; (2) the use of flame chemiluminescence as a fast, inferential emissions sensor for faster feedback; and (3) the robustness of the adaptive control strategy over the entire operability range and under a simulated perturbation mode. For the current study, a simulated injector perturbation scenario (partial fuel jet blockage) is utilized to examine the robustness of the optimization strategies. The results obtained illustrate the relative correlation of the different sensor strategies with system performance and the ability of the closed-loop control to maintain combustion performance in light of a simulated hardware perturbation.