Design and thermodynamic analysis of a thermal power plant operating with different low grade Turkish lignites and applying parametric analysis in order to increase exergy efficiency of the system

Politic restrictions in energy assurance and extreme increase in petroleum prices have directed Turkey towards energy and environment legislation to maximize the utilization of low grade local lignites, in which the country is relatively rich. In the context of the sustainability of these policies, Turkey has signed the Kyoto Protocol and taken the EU energy-environment policies into consideration as the main policy. The object of this study is to design a 245 MWe thermal power plant for operating with 10 different types of low grade lignites of Turkey and implementing of the various R&D studies. After modeling and simulation of the designed power plant, comprehensive energy and exergy analyses have been carried out in order to improve its energy and environmental performance. Exergy analyses have demonstrated that 90% of the total exergy loss of the power plant occurs in the boiler, and unlike energy analyses, actual energy efficiency must be in the boiler, not in the cooling system where only 1.5% of the total exergy loss occurs. Certain coefficients have been calculated for power plants fired with low grade local lignites, in order to determine directly the approximate fuels exergies and power plants exergy efficiencies with the help of the lower and higher heating values of the fuels and power plant energy efficiencies. Therefore, an approximate but highly practical tool has been obtained for reoffering the complicated exergy analyses by engineers.