The authors present the application of a method for gas turbine analysis, that they have recently introduced, based upon the selection of rotating components and on the study of off-design behaviour. The paper deals with an aero-derivative gas turbine, whose operating field is evaluated by an advanced cycle calculation which takes into account the fluid-dynamic and mechanical matching of the turbomachines.
Different regulation systems are considered, like variable-geometry compressor and turbine vanes, whose effect is combined with the variations in rotational speed of the gas generator device.
The simulation model allows definition of a performance map of the gas turbine, not only in terms of mechanical output and efficiency but also of pollutant emissions, as a result of the prediction of thermal NO formation inside the combustor.
The method leads to the establishment of an optimal control and regulation strategy with respect to a prescribed objective, i.e., either for maximum in energy saving or for the best compromise between performance and emission levels. Cases are examined with reference to both mechanical energy production and combined heat and power generation.