Prediction of the Transient Thermodynamic Response of a Closed-Cycle Regenerative Gas Turbine

Abstract

Instantaneous-response and transient-flow component models for the prediction of the transient response of gas turbine cycles are presented. The component models are based on applications of the principles of conservation of mass, energy, and momentum. The models are coupled to simulate the system transient thermodynamic behavior, and used to predict the transient response of a closed-cycle regenerative Brayton cycle. Various system transients are simulated using: the instantaneous-response turbomachinery models coupled with transient-flow heat-exchanger models; and transient-flow turbomachinery models coupled with transient-flow heat-exchanger models. The component sizes are comparable to those for a solar-powered Space Station (radial turbomachinery), but the models can easily be expanded to other applications with axial turbomachinery. An iterative scheme based on the principle of conservation of working-fluid mass in the system is used to compute the mass-flow rate at the solar-receiver inlet during the transients. In the process the mass-flow rate of every component at every time step is also computed. Representative results of different system models are compared and discussed.