Increasing exergy efficiency of a coal-fired thermal power plant via feedwater-heating repowering application

YILMAZOĞLU M. Z. , Erdogan A. A.

INTERNATIONAL JOURNAL OF EXERGY, vol.29, pp.263-281, 2019 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 29
  • Publication Date: 2019
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.263-281
  • Keywords: repowering, exergy, feedwater heating, thermal power plant, exergetic efficiency, ENERGY, OPTIMIZATION, BOILER
  • Gazi University Affiliated: Yes


This study presents an exergetic comparison when feedwater-heating repowering method is used in a coal fired thermal power plant. Design data for Soma-A Thermal Power Plant was used to calculate the exergetic efficiency before repowering. Secondly, the exergetic efficiency calculations were repeated for thermal power plant after feedwater-heating repowering method. It was found that exergy destruction (ED) in combustion chamber (boiler) decreased from 84% to 66%. However, exergy destruction for the combustion chamber of gas turbine (GT) was found to be 15%. Total exergy destruction increased from 54.4 MW to 69 MW. However, total exergy destruction per installed capacity decreased from 2.3 MW/MWel to 1.99 MW/MWel. In addition, exergetic efficiencies for the designed and repowered cycles were found to be 31% and 34%, respectively. In conclusion, the feedwater-heating repowering method can increase the exergetic efficiency of the coal fired thermal power plants.