A simulation model for transient behaviour of heavy-duty gas turbines

In this study, an analytical model is developed to characterize the transient behaviour of a heavy-duty gas turbine unit. While deriving models based on mass and energy conservation, the lack of essential variables such as air mass flow rate is a major problem. Constrained nonlinear optimization problems were served to obtain the unknown parameters based on experimental data. The objective functions were defined as the mean square of errors on compressor pressure ratio, compressor outlet temperature, gas fuel flow, the unit thermal efficiency, corrected outlet temperature and the generated power. The accuracy assessment was performed by comparing the responses of the model and the responses of real plant which indicated that the modelling error was less than 0.2 percent. The effect of changes in ambient conditions were also investigated by simulating open-loop model over a certain period of time. The results confirmed the accuracy of the developed model over a wide range of operations.