Energy 29 (2004) 2347–2358 www.elsevier.com/locate/energy Compressor intake-air cooling in gas turbine plants E. Kakaras  , A. Doukelis, S. Karellas Laboratory of Steam Boilers and Thermal Plants, Department of Mechanical Engineering, National Technical University of Athens, 9 Heroon Polytechniou Avenue, 15780, Zografou, Athens, Greece Abstract The generated power and efficiency of gas turbine plants depend on the temperature of the inlet air. At high ambient temperatures, a power loss of more than 20%, combined with a significant increase in spe- cific fuel consumption, compared to ISO standard conditions (15 v C), can be observed. The purpose of this work is to present a computer simulation of the integration of an innovative technology for reducing the intake-air temperature in gas turbine plants. Following a description of the air-cooling system, simulation results for two test cases are presented: a simple cycle gas turbine and a combined cycle plant. First, the effect of ambient air temperature variation on the power output and efficiency is presented for both cases. Next, the results from the integration of an evaporative cooler and of the air-cooling system under consideration are presented and discussed, demonstrating the gain in power output and efficiency that can be achieved. # 2004 Elsevier Ltd. All rights reserved. 1. Introduction The adverse effect of high ambient air temperatures on the power output of a gas turbine is twofold: as the temperature of the air increases, the air density and, consequently, the air mass flow decreases. The reduced air mass flow directly causes the gas turbine to produce less power output. On the other hand, the higher intake-air temperature results in an increase of the spe- cific compressor work and, therefore, in a further reduction of the power output. Depending on the type of the gas turbine, the electric output will decrease by a percentage between 6% and more than 10% for every 10 v C of intake-air temperature increase. At the same time, the specific heat consumption increases by a percentage between 1.5% and more than 4%. The straightfor- ward conclusion from the above discussion is that at temperatures of 40–45 v C, common in some southern European countries where a large number of gas turbines are used for electricity  Corresponding author. Tel.: +30-1-7723662; fax: +30-1-7723663. E-mail address: ekak@central.ntua.gr (E. Kakaras). 0360-5442/$ - see front matter # 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.energy.2004.03.043