Development and analysis of a solar-based integrated system with a CO2 Rankine power cycle

Abstract

The current work is a thermodynamic-based design and analysis of a solar-based integrated system for power production. In this regards, a reheat supercritical carbon dioxide (S-CO2) Rankine cycle is proposed. This cycle is then integrated with a parabolic trough collector (PTC) solar field, a thermal energy storage system and an absorption refrigeration system (ARS). A parametric study is then conducted, involving energy and exergy analyses of each subsystem and the overall integrated system. The system performance under different operating conditions is evaluated through energy and exergy efficiencies as well as energy and exergy based coefficients of performance (COP) for the absorption system. The heat energy losses and exergy destruction rates are also evaluated for different components. The effects of changing some radiation properties and operating conditions on the performance of the PTC solar field are investigated. This includes beam radiation incidence angle, receiver emittance and glass cover emittance. In addition, the impacts of changing these parameters on the overall integrated system energy and exergy efficiencies are illustrated. The energy and exergy efficiencies of the PTC are found to be 66.35% and 38.51%. The energy and exergy efficiencies of the reheat S-CO2 Rankine power cycle are examined under various operating conditions of the concentrated solar power (CSP) plants. The exergy destruction rates through the cycle components are determined and evaluated. The results show that the S-CO2 Rankine power cycle is expected to achieve energy and exergy efficiencies of 31.6%, and 57.5%, respectively. Under the same operating conditions, the energetic COP for ARS is about 0.7 and the exergetic COPex is 0.27. Accordingly, the overall integrated system energy (heat-to-electric) and exergy efficiencies become 11.73%, and 12.36%, respectively.