Title: Increasing exergy efficiency of a coal-fired thermal power plant via feedwater-heating repowering application
Authors: Mustafa Zeki Yilmazoglu; Altug Alp Erdogan
Addresses: Department of Mechanical Engineering, Gazi University, Ankara, Turkey ' Department of Mechanical Engineering, Gazi University, Ankara, Turkey
Abstract: 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.
Keywords: repowering; exergy; feedwater heating; thermal power plant; exergetic efficiency.
International Journal of Exergy, 2019 Vol.29 No.2/3/4, pp.263 - 281
Received: 28 Sep 2018
Accepted: 17 Feb 2019
Published online: 27 Jun 2019 *