Development of a program for transient behavior simulation of heavy-duty gas turbines

In this study, a program for analyzing the transient behaviors of heavy-duty gas turbines was developed. Focus was given to simulating a practical load-following operation. A distinct feature of our work is that all of the gas turbine components are modularized to enhance the expandability of the program. We used object-oriented programing for this purpose. Mass and energy balances and performance maps for the compressor and turbine were used for the modeling, and a multivariable numerical solving technique was used to enhance the numerical stability. The fundamental thermodynamic modeling of the program was validated by comparison of the transient response of a simulated gas turbine with that of a commercial program. PID control was adopted for simultaneous control of the rotational shaft speed and turbine exhaust temperature by the modulations of the fuel flow and the opening of the compressor inlet guide vane at the same time. The influence of the magnitude of load change and ramp rate was investigated. Stable control of the gas turbine was possible, even for a very rapid change of load.