Effect of Turbine and Compressor Inlet Temperatures and Air Bleeding on the Comparative Performance of Simple and Combined Gas Turbine Unit

The proper utilization of all the available forms of energy resources has become imminent to meet the power requirement and energy demand in both the developed and developing countries of the world. Even though the emphasis is given to the renewable resources in most parts of the world, but fossil fuels will still remain the main resources of energy as these can meet both normal and peak demands. Saudi Arab has number of power plant based on natural gas and fuel that are spread in all its regions. These power plants have aeroderivative gas turbine units supplied by General Electric Company as main power producing units. These units work on dual fuel systems. These units work as simple gas turbine units to meat peak demands and as part of combined cycle otherwise. The subject matter of this study is the performance of one of the units of a power plant situated near Riyadh city of Saudi Arab. This unit also works both as simple gas turbine unit and as a part of combined cycle power plant unit. A parametric based performance evaluation of the unit has been carried out to study both energetic and exergetic performance of the unit for both simple and combined cycle operation. Effect of compressor inlet temperature, turbine inlet temperature, pressure ratio of the compressor, the stage from which bleed off air have been taken and percentage of bleed off air from the compressor on the energetic and exergetic performance of the unit have been studied. The study reveals that all these parameters effect the performance of the unit in both modes of operation.