IJRRAS 13 (2) ● November 2012 www.arpapress.com/Volumes/Vol13Issue2/IJRRAS_13_2_19.pdf 549 EXERGY ANALYSIS OF A GAS TURBINE PERFORMANCE WITH EFFECT CYCLE TEMPERATURES Wadhah Hussein Abdul Razzaq Al- Doori Technical Institute/Al-Door, Foundation of Technical Education, Ministry of Higher Education and Scientific Research, Iraq Iraq/Salah Al-din/ Al-door/ Technical institute/Al-door/ House No. 06. HP: 009647703964452 / e-mail (wadhahh@yahoo.com) ABSTRACT To examine the degradation of energy during a practice, the production of entropy and the loss of work opportunities, exergy is analyzed. This analysis provides an alternative plan to ensure superior performance of a power plant. This study performed an exergetic analysis for a Baiji plant with a gas-turbine of capacity 159-MW. Each component of the system was tested in accordance with the laws of mass and energy conversion. The aspects under consideration were the quantitative exergy balance for the entire system and for each component, respectively. At different temperatures, rate of irreversibility of system components, efficiency of exergy and the efficiency flaws were highlighted for each component and for the whole plant. The exergy flow of a material is classified into the groupings of thermal, mechanical and chemical exergy in this study and a stream of entropy-production. Fuel oil of low heating value of 42.9 MJ/kg was used as the fuel. The evaluation addressed the question of how the fluctuations in cycle temperatures influence the exergetic efficiency and exergy destruction in the plant. The rate of exergy destruction in the turbine was around 5.4% whereas that in the combustion chamber was about 36.4%. When a 14°C rise was done in the temperature, exergy efficiency for the combustion chamber and the turbine was calculated to be 45.43% and 68.4%, respectively. According to the results of the study, the combustion chamber and turbine are found to be chief means of irreversibilities in the plant. Also, it was identified that the exergetic efficiency and the exergy destruction are considerably dependent on the alterations in the turbine inlet temperature. On the basis of these results, recommendations are presented for advancement of the plant. Keywords: Gas turbine, efficiency; exergy, irreversibility, performance. 1. INTRODUCTION Presently, a number of researchers such as Cengel and Boles [1]; Jones and Dugan [2]; Moran and Shapiro [3]; Aljundi [4], have chosen the topic of “exergy analysis in thermal design” and have provided considerable amount of literature on it. Basically the performance of a system is assessed by an exergy analysis as it is derived from the second law of thermodynamics which makes it rise above the limitations of an energy-based analysis. Exergy is annihilated in the system rather than conserved. The chief source of inefficiency of a system is the amount of irreversibility which is the exergy destruction. Thus, in a thermal system the location, the amount and the cause of thermodynamic deficiencies are determined by the exergy analysis evaluating the degree of exergy destruction [5-7]. The entropy-generation of the components is precisely calculated in the exergy analysis and this enables us to forecast the thermodynamic performance of an energy system and the efficiency of the system components [8]. There has been a rapid development in advanced approaches to study the intricate energy systems based on the second law of thermodynamics. This is due to the keen interest showed by researchers in energy efficiency and conservation. The phenomenon of exergy gives rise to one such performance analysis. The shortcomings of an energy-based study have been removed by an exergy-based system analysis. Exergy differs from energy as the former is destroyed rather than conserved in a system. Therefore, the position, amount and causes of system deficiencies have been determined by an exergy analysis used to evaluate the quantity of exergy destruction [9-12]. Such an analysis ensures the distinction between energy lost to the environment and internal irreversibility of the process. It is due to this that thermodynamic evaluation of energy conservation can be performed in an exergetic analysis [13-15]. Thermal processes are enhanced and irreversibilities in system components are measured effectively due to the statistics provided. Also, the role played by irreversibilities in the gross irreversibility of the whole plant is studied. Moreover, it provides a chance to reflect on the economic and developmental aspects for superior efficiency. Our research involved conducting an exergetic analysis for a 159-MW gas-turbine Baiji plant situated at Baiji, Iraq. Each component was studied under the light of laws of energy and mass conservation along