Thermal performance analysis of a direct-heated recompression supercritical carbon dioxide Brayton cycle using solar concentrators

Research output: Contribution to journalArticle

Researchers

Research units

  • Nanjing Institute of Technology
  • Southeast University

Abstract

In this study, a direct recompression supercritical CO2 Brayton cycle, using parabolic trough solar concentrators (PTC), is developed and analyzed employing a new simulation model. The effects of variations in operating conditions and parameters on the performance of the s-CO2 Brayton cycle are investigated, also under varying weather conditions. The results indicate that the efficiency of the s-CO2 Brayton cycle is mainly affected by the compressor outlet pressure, turbine inlet temperature and cooling temperature: Increasing the turbine inlet pressure reduces the efficiency of the cycle and also requires changing the split fraction, where increasing the turbine inlet temperature increases the efficiency, but has a very small effect on the split fraction. At the critical cooling temperature point (31.25 C), the cycle efficiency reaches a maximum value of 0.4, but drops after this point. In optimal conditions, a cycle efficiency well above 0.4 is possible. The maximum system efficiency with the PTCs remains slightly below this value as the performance of the whole system is also affected by the solar tracking method used, the season and the incidence angle of the solar beam radiation which directly affects the efficiency of the concentrator. The choice of the tracking mode causes major temporal variations in the output of the cycle, which emphasis the role of an integrated TES with the s-CO2 Brayton cycle to provide dispatchable power.

Details

Original languageEnglish
Article number4358
Pages (from-to)1-17
Number of pages17
JournalEnergies
Volume12
Issue number22
Publication statusPublished - 15 Nov 2019
MoE publication typeA1 Journal article-refereed

    Research areas

  • Concentrated solar power, Direct-heated, Parabolic trough, Performance analysis, Supercritical CO Brayton cycle

Download statistics

No data available

ID: 39587771