Recuperators investigation for high temperature supercritical carbon dioxide power generation cycles

• Published in: Applied thermal engineering Vol. 125; pp. 1094 - 1102
• Main Authors: Gkountas, Apostolos A., Stamatelos, Anastassios M., Kalfas, Anestis I.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.10.2017; Elsevier BV
• Subjects: Carbon dioxide; Comparative analysis; Compressing; Computer simulation; Deviation; Electric power generation; Energy conversion efficiency; Flow characteristics; Heat transfer; Heat transfer coefficients; High temperature; Mathematical models; Printed-circuit heat exchangers; Recompression cycle; Recuperators’ analysis; Regenerators; Simulation; Supercritical CO2; Supercritical processes; Thermodynamic efficiency; Thermodynamic modeling; Thermodynamic modeling; Printed-circuit heat exchangers; Supercritical CO2; Recompression cycle; Recuperators’ analysis
• ISSN: 1359-4311; 1873-5606
• DOI: 10.1016/j.applthermaleng.2017.07.092

•Steady-state modeling of s-CO2 recompression cycle comparing two different tools.•Segmental design method and analysis of PCHE recuperators.•Heat transfer and fluid flow characteristics effect on recuperators effectiveness.•Investigation of operating conditions resulting in an efficiency greater than 46%. Supercritical carbon dioxide (s-CO2) Brayton cycles are a promising technology for the next generation power conversion cycles, attaining equivalent or higher cycle efficiency compared to conventional power cycles at similar temperatures (550–750°C). The recompression cycle attracts the main research interest among the s-CO2 layouts. Recompressing a fraction of the flow without heat rejection, results to an increase in thermal efficiency, while the majority of heat transfer occurs in recuperators. In this study, a thermodynamic analysis of a 600MWth power cycle has been carried out using two different simulation tools to model the recompression system. The analysis focuses on the parameters that have the most significant impact on the components and cycle efficiency. A segmental analysis of the recuperators took place to assess the effect of flow characteristics on the heat transfer. Finally, a comparative analysis of the results of the two simulation tools versus the results of a reference cycle from literature is carried out, showing that the prediction of the overall heat transfer coefficient and recuperator effectiveness between the developed code and reference model has a maximum deviation of 4%, whereas the prediction deviation between the commercial software and reference model is about 2.8%.