Title: Influence of reference temperature on exergy and exergoeconomic performance of a natural gas fired thermal power plant

Authors: Ambrose N. Anozie; Oludare J. Odejobi

Addresses: Applied Thermodynamics and Process Design Research Laboratory, Department of Chemical Engineering, Obafemi Awolowo University, Ile-Ife 220005, Nigeria ' Applied Thermodynamics and Process Design Research Laboratory, Department of Chemical Engineering, Obafemi Awolowo University, Ile-Ife 220005, Nigeria

Abstract: The influence of reference temperature on exergy and exergoeconomic performance parameters of a thermal plant was investigated. The plant was simulated using HYSYS (2003) process simulator software and the exergy and exergoeconomic analyses were done using Microsoft EXCEL spreadsheet. As reference temperature increased from 15°C to 35°C, exergy efficiency decreased from 11.7% to 11.5% and irreversibility increased from 1790 MW to 1812 MW. Also, overall exergy cost decreased from 6650.78 MW to 6055.40 MW and monetary cost from $75,343.84/h to $68,430.19/h. The optimum (base case) reference temperature, where the exergy and the monetary exergy loss costs were at minimum, was found to be 30°C. At this temperature both the condenser and boiler units made significant contributions to the process exergy and monetary exergy loss costs. The study concluded that the performance of the thermal plant depends on reference temperature, efficiencies of condenser and boiler units.

Keywords: reference temperature; irreversibility; exergetic efficiency; exergy loss costs; exergoeconomic loss cost; exergy improvement potential; exergoeconomic improvement potential; natural gas; thermal power plants; process simulation; condenser; boiler.

DOI: 10.1504/IJEX.2013.055780

International Journal of Exergy, 2013 Vol.13 No.1, pp.102 - 123

Received: 16 Jan 2012
Accepted: 11 Sep 2012

Published online: 08 Aug 2013 *

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