Investigation of a combined cycle power plant coupled with a parabolic trough solar field and high temperature energy storage system

Abstract

This study was aimed at exergetically investigating a combined cycle power plant coupled with a parabolic trough solar field and high temperature energy storage system. Thermodynamic modeling of the combined cycle was conducted by ASPEN HYSYS simulation software, while the modeling of solar and energy storage section was carried out using MATLAB software. The main goal of the present research work was to reveal the reasons and sources of the thermodynamic losses occurring in the power plant based on the thermodynamic outcomes obtained from modeling. After writing the exergy balance equations for all the subunits of the power plant, their exergetic performance parameters were measured individually. Moreover, the effect of different influential parameters such as gas turbine inlet temperature and outlet pressure, and the R113 working fluid mass flow rate on the exergy and electrical efficiencies of the whole system was also investigated and scrutinized. The exergetic value of the net electric power was found to be 93,580 kW. The overall exergy destruction of the system stood at 216,710 kW. The contribution of solar and energy storage combination, as the main subunit wasting exergy, to the overall exergy destruction of the system was determined at 43%. Moreover, combustion chamber subunit stood in the next rank in terms of exergy destruction, contributing 15.7% of the overall exergy destruction of the power plant. The overall exergy efficiency and electrical efficiency of the power cycle was determined at 38.2% and 47%, respectively.