Dynamic simulation of the rapid load-change performance of a large-scale gas turbine combined cycle power plant

The fluctuating power output of renewable energy sources (REs) renders the electric grid unstable, and thus, a realistic approach must be established to compensate for the load fluctuations associated with RE-based power generation. The gas turbine combined cycle power generation (GTCC) with a rapid start-up and high ramp rate is a potential solution to solve the problem. This study presented the feasibility of an advanced GTCC focused on the rapid load following operation through dynamic simulation. A dynamic model of an advanced GTCC was constructed with the Modelica-based tool. It was found that the load-following capability of the GTCC can be improved by increasing the operational performance of the GT, but the steam condition fluctuation such as steam temperature in the steam bottoming system becomes larger. A simulation for increasing the temperature of the exhaust gas at the inlet of the heat recovery steam generator during low load band operation was conducted. The potential of this approach to suppress the steam temperature fluctuation was highlighted through this simulation.