Dynamic modeling of a hybrid solar-combined cycle power plant (ISCC) using a solar field based on parabolic trough solar collector - Start-up and shutdown of the solar field

Abstract

The hybridization of combined-cycle power plants with solar energy is an attractive means of reducing carbon dioxide emissions. That could be an intermediate step on the way to a 100 % renewable era. Parabolic Trough Solar Collector (PTSCs) constitute a proven source of thermal energy for industrial process heat and pour generation. Parabolic trough solar power plants are, as of today, the concentrating solar power (CSP) technology with the largest track record. The purpose of this study is to simulate the impact of converting an existing combined cycle power plant to an integrated solar combined cycle (ISCC) plant using a solar field based on a parabolic trough solar collector system. The solar field is used to generate solar steam which is supplied to the steam turbine to increase the power output (by around 15%) during the sunny periods and reduce the fuel consumption, which results in a reduction in CO2 emissions. The objectives of this study are: the sizing of the main components of the solar system, the assessment of the impact of start-up phase of the solar field on the Solar Hybrid Power Plant dynamic behavior and the demonstration of the capability of the model to simulate the operating conditions of an ISCC power plant. A detailed dynamic model of the ISCC has been developed in Modelica. The component models used belong to the ThermoSysPro library developed by EDF and released under open source license. The paper also gives the results of the dynamic simulation for selected scenarios. This paper focuses on the hybridization of Parabolic Trough Power Plants with an existing GCC and the operation mode of the hybrid system is booster type. The solar fraction is then limited by the GCC part which remains unchanged.