Combustion characteristics of pressurized methane-air combustor for chemical gas turbine system

Chemical Gas Turbine System is expected to improve greatly a thermal efficiency compared to the conventional systems. In this system the combustor which drives the first gas turbine is operated under fuel-rich condition. This fuel-rich combustor plays a central role in the improvement of thermal efficiency. In this study, the profiles of temperature and species concentrations in a model combustor are measured when it is operated under fuel-rich and pressurized conditions to obtain fundamental data fbr designing the practical combustor in the chemical gas turbine system Moreover, we develop the numerical combustion simulation to predict the combustion characteristics of turbulent methane-air diffusion flame in the model combustor. The structure of fuel-rich flame in the model combustor is clarified by the measured profiles of CO and H-2 concentrations. When the combustor operated under fuel-rich conditions, the measured concentrations of CO and H-2 are considerably high in the middle of the combustor. In this study, moreover, the results calculated by the combustion simulation are compared to the measured data. From the comparisons between measured and calculated radial profiles of species concentrations in the combustor, it is clear that this simulation conforms fairly well to the measured profiles in the upstream region of the combustor.