In this study, operation of compressor station has been investigated by exergy approach. Exergy analysis is a thermodynamic method which shows the irreversibility of a system quantitatively. Gas compressors are used to compensate the pressure drop along the gas pipeline significantly. The compression process causes temperature rise of gas; in this regard gas cooler is applied to reduce the temperature. The compressors are run at variable speed; fuel consumed in combustion chamber is changed accordingly. The case study is focused on transmission of sour gas through IGAT5 pipeline, located in south of Iran.exergy destruction, exergetic efficiency, fuel consumption of station and effect of each elements of station on total destruction is measured for speed range of 5200 to 7000 rpm of compressor. It is showed that about 90 present of destruction is possessed by turbine. Fuel consumption of station depending on compressor speed and increasing trend is seen that started from 0.9236 kg/s at 5200 rpm and ended to 1.2 kg/s at 7000 rpm.

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