javad yazdanpanahi - ’Ph.D Student of Mechanical Engineering; University ofSistan and Baluchestan; Department of Mechanical Engineering
faramarz sarhaddi - ۲Assistant professor, University of Sistan and Balm.-hestan , Department of Mechanical Engineering

In this paper, we investigate the overhaul ofa gas unit, FRAME 5, at the Zahedan gas power plant. Unit G15 of the power plant was not able to generate more than 114 MW following the last overhaul in 2012 due to the constraint of wheel space temperature and exhaust temperature. Thus, it was shut down for overhaul in 2014 after 4016 hours of operation. The size of all clearances was set in accordance with the manufacture1‘s standard and finally, unit efficiency increased from 18.02 % before to overhaul to 24/19 % after the overhaul. According to the operation instruction, the unit has a temperature limit for wheel space of approximately 426°C. lhcrefore, wheel space temperature was 430°C before overhaul with a load of l 1.4 MW and was 430°C before afier the overhaul with a load of 16.5 MW indicating an increase in active load with a similar temperature.Exhaust temperature limit of the unit is 500 degrees Celsius. Therefore, there was no change in the exhaust temperature ofthe unit afier the overhaul.

Gas turbine, Efliciencjv, Maintenance, Assembiy