## 1 Introduction  
Iran's total power generation capacity by thermal power plant stands at 66,000 MW (80%) in 2020, of which 37.8% are related to a gas turbine plant and 38.4% relate to combined power plants. So, the role of the gas turbine power plant is very substantial individually and in the combined power plants [1; 2; 3]. The performance of the gas turbine is affected by some important parameters that consist of the compression ratio, ambient temperature, and pressure, humidity, turbine inlet temperature, specific fuel consumption, and air to fuel ratio [4; 5; 6]. Due to the widespread use of gas power plants, it is important to consider the impact of these parameters on the efficiency of the gas turbines. Since the air of the combustion process in the gas turbine is provided by atmospheric air, so the specific properties of the atmospheric air in that reign is highly important. As the ambient temperature is one of the thermodynamic parameters, this factor has been studied extensively. Additionally, as the process of the gas turbine is the constant volume process, the investigation of this factor is being more highlighted [7; 8]. The output power of gas turbine changes by an average of 10% since ambient temperature (compressor intake air) changes by 10 \({}^{\circ}\)C [9; 10; 11]. So, the performance of the gas turbine can be deteriorated significantly in the hot region or the summer season. On the other hand, the two operational considerations of the gas turbine are extensive regarding the application of the gas turbine. Firstly, a large amount of the output power of the turbine is required to drive the compressor (30-40%) in the gas power plant [12]. Secondly, the exhaust gas in the open gas power plant is quite high over 500 \({}^{\circ}\)C [7; 13]. This excess heat in flue gas from the gas turbine can be used as a source of high-temperature resources in another cycle, unless it may cause thermal pollution of the atmosphere. The remedy for this high-temperature exhaust gas in the open gas cycle is neither to add bottoming steam cycle (combined cycle) [7; 13] or using a heat recovery steam generator (HRSG) [14; 15], as well as a combination of the solid oxide fuel cell and gas cycle. The application of HRSG on the performance of gas turbines was examined for a steam power plant in Iran. The results revealed that adding an HRSG to a gas turbine, model Mitsubishi-701G2, could increase the energy and exergy efficiencies and power generation up to 52.19%, 50.9%, and 485.8 MW, respectively [16]. A general overview of different types of turbine air cooling methods in the gas power plants was examined. The three different air cooling methods consist of evaporative cooling, refrigeration cooling, and evaporative cooling of precompressed air that were introduced and examined [17]. The performance of three turbine air cooling methods applications including; evaporative media (EM), mechanical chiller (MC), and a novel idea of turbo-expander (TE) were conducted in the gas turbine of a refinery in Iran. The result showed that the efficiency improvement in the gas turbine cycle was 5% for mechanical chiller, 3% for evaporative media, and 4% for turbo-expander systems [18]. [PERSON] et al. [19] analyzed the effects of different methods of inlet air cooling systems for the gas turbine cycle. The results showed that evaporative cooling boosted power by up to 8.7% and efficiency by up to 3.3%. On the other hand, the fogging system improved power by up to 9.5% and efficiency by up to 3.5%. Moreover, the mechanical chiller reduced the temperature by 20-45 \({}^{\circ}\)C; enhancing the net power by 7-24.3% and improving the efficiency by 2.4-18.8%, whereas the absorption chillers enhanced the net power by up to 12.1-37.3% and improved the efficiency by up to 31.5%. The performance usage of absorption chiller with lithium-bromide absorbent on the cooling of intake air of a gas turbine, operated either as a simple cycle or a combined cycle was examined in the arid and tropical climates (Thailand).