**ABSTRACT**

In this article, exergy, exergoeconomic and exergoenvironmental analysis of a gas turbine cycle and its optimization has been carried out by MOPSO algorithm. In this paper, three objective functions namely total cost rate, exergy efficiency of cycle and CO2 emission rate have been considered. The design variables considered are: compressor pressure ratio, combustion chamber inlet temperature, gas turbine inlet temperature, compressor and gas turbine isentropic efficiency. In this paper, the impact of change in gas turbine inlet temperature and compressor pressure ratio on CO2 emission rate as well as impact of changes in gas turbine inlet temperature on exergy efficiency of the cycle has been investigated in different compressor pressure ratios. The results showed that with increase in compressor pressure ratio and gas turbine inlet temperature, CO2 emission rate decreases, that is this reduction is carried out with a steeper slope at lower pressure compressor ratio and gas turbine inlet temperature. The results showed that exergy efficiency of the cycle increases with increase in gas turbine inlet temperature and compressor pressure ratio. The sensitivity analysis of fuel cost changes was performed on objective functions. The results showed that at higher exergy efficiencies that total cost rate is greater, sensitivity of fuel cost optimum solutions is greater than Pareto curve with lower total cost rate. Also, the results showed that sensitivity of changes in fuel cost rate per unit of energy on total cost rate is greater than the rate of CO2 emission.

**KEYWORDS**

PAPER SUBMITTED: 2016-10-11

PAPER REVISED: 2017-03-21

PAPER ACCEPTED: 2017-03-21

PUBLISHED ONLINE: 2017-04-08

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