Effect of Actual Recuperators’ Effectiveness on the Attainable Efficiency of Supercritical CO[sub.2] Brayton Cycles for Solar Thermal Power Plants

• Published in: Energies (Basel) 2022-10, Vol.15 (20)
• Main Authors: Stamatellos, George, Stamatelos, Tassos
• Format: Article
• Language: English
• Subjects: Design and construction; Solar energy; Solar power plants; Thermodynamic cycles
• ISSN: 1996-1073; 1996-1073
• DOI: 10.3390/en15207773

One of the most promising concentrated solar power technologies is the central receiver tower power station with heliostat field, which has attracted renewed research interest in the current decade. The introduction of the sCO[sub.2] recompression Brayton cycles in the near future installations instead of the Rankine cycle is very probable, due to the prospects of a significant efficiency improvement, process equipment size and capital cost reduction. In this study, energy and exergy analysis of a recompression Brayton cycle configuration for a central receiver power station are performed. Special emphasis is given to the computation of actual performance for the High-Temperature Recuperator and the Low-Temperature Recuperator. The results define realistic thermal and exergetic efficiency limits for the specific cycle configurations applied on a central receiver solar power plant with variable turbine entry temperature. Thermal efficiency, predicted with the improved accuracy of heat exchanger computations, does not exceed the 50% target. Overall, a realizable total power plant efficiency of 37% at 900 K turbine entry temperature is predicted, which is a significant improvement on the current state-of-the-art with steam Rankine cycles.