Int. J. Exergy, Vol. 8, No. 3, 2011 247 Copyright © 2011 Inderscience Enterprises Ltd. The effect of elevated inlet air temperature and relative humidity on Gas Turbine cogeneration system: exergy assessment F.N. Alasfour, S.F. Al-Fahed and H.K. Abdulrahim* Mechanical Engineering Department, Kuwait University, P.O. Box 5969, Safat 13060, Kuwait E-mail: alasfour@kuc01.kuniv.edu.kw E-mail: alfahed@kuc01.kuniv.edu.kw E-mail: hassan.abdulrahim@ku.edu.kw *Corresponding author Abstract: This research aims to quantify the exergy destructions of Gas Turbine (GT) cogeneration system under different inlet air temperatures and humidity. Three different cogeneration schemes were examined in this research: conventional GT, GT-Single Pressure HRSG and GT-Dual Pressure HRSG. A parametric study was carried out in terms of exergy destruction and second-law efficiency. The exergy utilisation factor had been investigated in this research. Results showed that inlet air temperature and relative humidity play an important role in determining exergetic performance. Integrating GT with dual pressure HRSG can be considered as an option during summer season and would improve the production of electricity and desalted water. Keywords: GT; gas turbine; HRSG; heat recovery steam generator; cogeneration; exergy utilisation factor; exergy destruction; elevated inlet air temperature; relative humidity. Reference to this paper should be made as follows: Alasfour, F.N., Al-Fahed, S.F. and Abdulrahim, H.K. (2011) ‘The effect of elevated inlet air temperature and relative humidity on Gas Turbine cogeneration system: exergy assessment’, Int. J. Exergy, Vol. 8, No. 3, pp.247–264. Biographical notes: Fuad N. Alasfour is an Associate Professor at Kuwait University. He received his PhD in 1989 in Mechanical Engineering from the University of Colorado at Boulder, USA. His major fields include combustion, alternative fuels and desalination. Sami F. Al-Fahed is an Associate Professor at Kuwait University. He received his PhD in 1983 in Mechanical Engineering from Catholic University of America, USA. His major fields include, heat transfer enhancement using micro-fin tubes and twisted tape inserts; thermal comfort analysis; flow of impinging jet; flow over axisymmetric cylinders. Hassan K. Abdulrahim is a Senior Lecturer Assistant at Kuwait University. He received his PhD in 2006 in Mechanical Engineering from Cairo University, Egypt. His major fields of research include thermal systems modelling and simulation; power generation; desalination and optimisation.