A gas turbine dynamic model for simulation and control

he useful life of gas turbines and the availability of power after start-up depend on their transient response. For this reason, several articles have been written on the dynamic simulation of gas turbine systems in electrical generation, cogeneration, and marine applications. The simulations typically rely on performance maps and time lags extracted from manufacturer's specifications. This work was undertaken to increase the generality of turbine models over what can be obtained from performance maps. The paper describes a mathematical computer model developed to investigate the dynamic response of a simple single-shaft gas turbine system. The model uses design parameters normally incorporated in gas turbine design (e.g. load coefficient, flow coefficient, and deHaller Number) as well as compressor and turbine stage geometry and compressor and turbine material properties. A dynamic combustion chamber model is also incorporated. Other input parameters are included to enable the model to be adaptable to various system sizes and environments. The model was formulated in a graphical interface, and the results of several trials are displayed. The influence of important parameters (e.g. fuel-air ratio, IGVs, load, efficiencies) on turbine response from a "cold" start and from steady-state is studied. To gain further insights into the response, a start-up procedure similar to that reported in the literature for an industrial gas turbine system is simulated. Because of the approach used, the computer model is easily adaptable to further improvements and combined simulation of turbines and control systems.