Nitric oxide formation analysis using chemical reactor modelling and laser induced fluorescence measurements on industrial swirl flames

This thesis investigates nitric oxide formation in the combustion of fuel compositions representative of those produced by the power generator gas turbines. As power generation gas turbine manufacturers and operators strive for improvements in thermal efficiency while abiding by the emissions regulation put into place, more detailed understanding of formation of different emissions is required to accurately simulate combustion of increasingly volatile gaseous fuel supplies. Detailed modelling of an industrial scale high-pressure generic swirl burner has been carried out to predict the formation of oxides of nitrogen at exhaust. Three new models are proposed based on the models available in the literature and simulation results are compared against each other as well as with the experimental data. The predictions from the selected model at different conditions has been appraised against the experimental results using several chemical kinetics mechanisms from the literature to validate the proposed chemical reactor model. Nitric oxide formation analysis is also carried out by taking in-flame nonintrusive laser induced fluorescence measurements for the first time on industrial swirl flames with a range of gaseous fuel. These experimental nitric oxide formation distributions are supported through the use of experimentally derived heat release intensities and numerical calculations. Changes in NO formations at different physical conditions with methane and methane-hydrogen fuel blends are discussed. Two calibration techniques are discussed and performed at the latter part of the thesis for quantification of the qualitative nitric oxide distribution data from this study in future. Data generated from this investigation provide opportunities for future validation work of chemical kinetics modelling and computational fluid dynamics analysis. In addition to that, results from this thesis will also inform gas turbine manufacturers on potential burner design modifications for better management of oxides of nitrogen emissions. Based on this work, future investigations may focus on quantitative nitric oxide formation analysis in alternative fuels like ammonia-methane-hydrogen blends