Exergy and Exergoeconomic analysis of Qeshm cogeneration plant

Exergoeconomic is the branch of engineering that combines exergy analysis with economic constraints to provide the system designer with information not available through conventional energy analysis and economic evaluation. In this study, exergy and exergoeconomic analysis has been performed for Qeshm cogeneration power plant. This cogeneration system can produce 26 MW electricity and 9000 m3 /day distilled water. Firstly, according to the mass and energy balance equations for cogeneration system’s component thermodynamic variables have been determined. Then, exergy analysis must be performed and exergy destruction of each component and its portion in the total exergy destruction can be determined. In order to determine cost of products, cost balance equation must be written for each component. The results of exergy analysis show that the maximum irreversibility is corresponding to the combustion chamber with the value of 11019.25 kW, and those of heat recovery steam generator (HRSG) and multi effect desalination with thermal vapor compression (MED-TVC) are 10305.43 kW and 9260.93 kW, respectively. The cost of producing electricity power is 10 $/MWh and the cost of producing distilled water is about 2 $/m3. Finally, the total cost of the understudy cogeneration cycle is in good agreement with the other cogeneration plant.