Research Article

Energetic and exergetic analysis of Rankine cycles for solar power plants with parabolic trough and thermal storage

Power Engineering Faculty, University Politehnica of Bucharest, Splaiul Independentei, 313, Bucharest 060042, Romania

^⁎ e-mail: victor.cenusa@energ.pub.ro

Abstract

The paper analyzes the “secondary” circuit (for thermodynamic conversion) of a Concentrated Solar Power (CSP) plant with thermodynamic cycle, whose mirrors field supplies a thermal power, averaged over a sunny day, of about 100 MW heat. We study the case of parabolic trough solar collector using silicone oil in the “primary” circuit, which limits the peak temperature below 400 °C. The “primary” circuit uses thermal storage, allowing a delay between the power generation in rapport with the solar energy capture. We choose a water-steam cycle, type Hirn. For increasing its efficiency, it has regenerative feed water preheating and steam reheating. We compared, energetic and exergetic, two types of cycles, using a numerical model with iterative structure, developed by the authors. The results showed that the simplified design achieves practically the same thermodynamic performances with the advanced one.