Influence of ambient temperature on the performance of repowered combined cycle power plant

Abstract EN

A performance study was conducted on the combined cycle power plant (CCPP), which is one of the most important options for replacement and repowering of the available steam power plant.

The thermodynamic performance of these plants depends on the ambient temperature which varies considerably from one season to another.

The objective of the current work is to investigate the effects of these variations on the performance of combined cycle power plants.

In this study AL-Mussaib thermal power plant has been chosen for repowering, for this purpose, AL-Khairat gas turbines are used and the effect of duct burner is investigated.

The repowered combined cycle power plant (RCCPP) consists of four gas turbines and four heat recovery steam generator (HRSG) with one steam turbine was associated with the unit in this model.

The theoretical analysis was made according to both first and second laws of thermodynamic analysis.

A generalized computer program was prepared by Fortran 90 for this purpose.

It is found that the net power output, thermal and exergy efficiencies of the RCCPP increases as the ambient temperature decreases.

The mass flow rate of steam decreases with the increase of ambient temperature at constant compressor pressure ratio and turbine inlet temperature (TIT).

The exergy destruction in the combustion chamber and HRSG decreases while, the exergy destruction of the condenser increases greatly as the ambient temperature increases