International Journal of the Physical Sciences Vol. 6(14), pp. 3539-3550, 18 July, 2011 Available online at http://www.academicjournals.org/IJPS DOI: 10.5897/IJPS11.272 ISSN 1992 - 1950 ©2011 Academic Journals Full Length Research Paper Thermodynamic performance analysis of gas-turbine power-plant M. M. Rahman 1,2 , Thamir K. Ibrahim 1 * and Ahmed N. Abdalla 3 1 Faculty of Mechanical Engineering, Universiti Malaysia Pahang, Tun Razak Highway, 26300 Gambang, Kuantan, Pahang, Malaysia 2 Automotive Engineering Centre, Universiti Malaysia Pahang, Tun Razak Highway, 26300 Gambang, Kuantan, Pahang, Malaysia 3 Faculty of Electrical and Electronic Engineering, Universiti Malaysia Pahang, Tun Razak Highway, 26300 Gambang, Kuantan, Pahang, Malaysia. Accepted 04 April, 2011 This paper was presented the parametric study of thermodynamic performance on gas turbine power plant. The variation of operating conditions (compression ratio, turbine inlet and exhaust temperature, air to fuel ratio, isentropic compressor and turbine efficiency, and ambient temperature) on the performance of gas turbine (thermal efficiency, compressor work, power, specific fuel consumption, heat rate) were investigated. The analytical formula for the specific work and efficiency were derived and analyzed. The programming of performance model for gas turbine was developed utilizing the MATLAB software. The results show that the compression ratio, ambient temperature, air to fuel ratio as well as the isentropic efficiencies are strongly influence on the thermal efficiency. In addition, the thermal efficiency and power output decreases linearly with increase of the ambient temperature and air to fuel ratio. However, the specific fuel consumption and heat rate increases linearly with increase of both ambient temperature and air to fuel ratio. Thus the thermodynamic parameters on cycle performance are economically feasible and beneficial for the gas turbine operations. Key words: Gas turbine, compression ratio, air to fuel ratio, thermal efficiency, power, turbine inlet temperature. INTRODUCTION The gas turbine (GT) performance is affected by component efficiencies and turbine working temperature. The effect of temperature is very predominant for every 56°C increase in temperature; the work output increases approximately 10% and gives about 1.5% increase in efficiency (Johnke and Mast, 2002). Overall efficiency of the gas turbine cycle depends primarily upon the pressure ratio of the compressor. It is important to realize that in the gas turbine the processes of compression, combustion and expansion do not occur in a single component as they occurred in a reciprocating engine. It is well known that the performance can be qualified *Corresponding author. E-mail: thamirmathcad@yahoo.com. with respect to its efficiency, power output, specific fuel consumption as well as work ratio. There are several parameters that affect its performance including the com- pressor compression ratio, combustion inlet temperature and turbine inlet temperature (TIT) (Mahmood and Mahdi, 2009, Rahman et al., 2010). Taniquchi and Miyamae (2000) were carried out the study on the effects of ambient temperature, ambient pressure as well as the temperature of exhaust gases on performance of gas turbine as shown in Figure 1. There is an obvious drop in the power output as the ambient air temperature increases, if an increase of intake air ambient temperature from ISO condition 15 to 30°C which is 10% decrease in the net power output. This is particularly relevant in tropical climates where the temperature varies 25 to 35°C throughout the year (Boonnasa et al., 2006).