Parabolic trough solar collectors integrated with a Kalina cycle for high temperature applications: Energy, exergy and economic analyses

As a promising option for future power generation is the concentrating solar power systems with various types, among which Parabolic Trough Solar Collectors (PTSC) are the most proven technology with lowest cost available today. Benefits of this renewable energy source are challenged by means of relatively low energy conversion efficiency. To overcome the dilemma, one approach is employing an efficient thermodynamic power cycle in order to enhance the overall power plant efficiency. The Kalina cycle (KC) is considered as an efficient alternative over the conventional or organic Rankine cycles in last few years. In the present work, the integration of a novel configuration of the KC, which is proper for utilizing high temperature heat sources, with PTSC is proposed and analyzed. Thermal, thermodynamic and economic models are developed to investigate the integrated system performance from the viewpoints of energy, exergy and economics. The results indicate that, exergy efficiencies of around 64% is achievable for power cycle unit while the overall power plant exergy efficiency reaches to around 14%. The results of economic analysis revealed that if a lower LCOE is to be reached increment of the number of collectors per row is more beneficial than the increment of parallel rows of the collectors.