Thermodynamic Analysis of a Gas Turbine Power Plant Modelled with an Evaporative Cooler

Abstract

In this paper the performance enhancement of gas turbine power plants by cooling the compressor intake air with an evaporative cooler is studied. This study investigated the effect of inlet air cooling system on the performance of an existing gas turbine power plant in Nigeria. The results show that for each 5 o C decrease of inlet air temperature, net output power increases around 5-10% and the thermal efficiency increases around 2-5%. It is shown that the amount of this increase is higher when the pressure ratio is high and turbine inlet temperature is low. The results of this study shows that retrofitting of the existing gas turbine plant with inlet air cooling system gives a better system performance and may prove to be an attractive investment opportunity to the Nigeria government and stakeholders of the plant.

Study on Performance Improvement and Economical Aspect of Gas Turbine Power Plant Using Evaporative Cooling System

“…The extent of the evaporation and the decreased of temperature is inversely proportional to the percentage of a humidity in the air stream [5], as shown in the saturation process in the psychrometric chart in Figure 4.…”

“…According to Santos et al [3] and Oyedepo et al [5], the following is the thermodynamic calculation for an open simple gas turbine cycle. In the existing condition or without a cooling system, the compressor inlet temperature is equal to ambient temperature, thus the inlet pressure is given by…”

“…The specific fuel consumption (SFC) compares the ratio of the fuel used by an engine to a characteristic power such as the amount of power produced by the engine [5]. SFC is determined by equation:…”

“…Several studies have been done related to the issue of power augmentation, for simple cycle and combined cycle gas turbine using evaporative cooling technique [2][3][4][5][6][7][8][9]. Hamdan et al [2] conducted a study on the performance improvement of a simple cycle gas turbine with a nominal rating of 250 MW.…”

Comparative thermo-economic analysis of multi-fuel fired gas turbine power plant

“…Energy demand in Nigeria has been rising and only about 50% of the total population have access to grid electricity [2]. Meanwhile, most of the energy demand are currently being met by peak load generation plants such as gas and combined gas/steam turbine power plants, which are contributing approximately 60.7% of the total installed capacity of the nation, as at 2012 [3]. Over the past three decades, gas turbines have become dominant sources of power for large scale power generation and for mechanical drives application.…”