ABSTRACT
Integrated Solar Combined-Cycle (ISCC) technology combines the benefits of solar
energy with the benefits of a combined cycle. The solar resource partially substitutes
the fossil fuel. In this paper, a thermodynamic exergy analysis of the integrated solar
combined cycle power plant in Egypt was implemented. The data is taken from the
design documentations of the plant as well as the plant records. Exergy-based
performance analysis based on the second law of thermodynamics overcomes the
limit of studying the system based on the first law of thermodynamics. It assesses the
magnitude of exergy destruction in each part of the system. The plant is a 135 MWe
hybrid power plant composed of a combined cycle and a 20 MWe solar thermal plant.
Exergy destruction throughout the plant is quantified and illustrated using an exergy
flow diagram. The exergitic efficiency of each component of the ISCC is calculated.
The results showed that the overall thermal efficiency and the 2nd law efficiency of the
ISCC accounted for 32% and 40.8%, respectively. Also, it was revealed that the
combustion chamber and the solar field represent the sites of the highest exergy
destruction in the ISCC (34 % and 42.1% respectively). The sources of the exergy
destruction in the combustion chamber and the solar field are discussed in order to
identify the possibility to enhance the performance of the components of major
exergy destruction.