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![Figure 1. Installed capacity and main producing companies[1].](profile/Saleh-Baakeem/publication/312625572/figure/fig1/AS:613508890755074@1523283326376/Installed-capacity-and-main-producing-companies1_Q320.jpg)
Gas turbine units are widely used in KSA and other countries particularly during the peak demands and in inland regions. They produce about 50% of the total capacity of power generation in the kingdom. Despite their numerous advantages, their thermal efficiency remains very low and their resulting environmental impacts are significant. In this stud...
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... turbines, considered constant volumetric flow rate machines, are widely used to produce electricity particularly in inland regions. As ambient air is used as working fluid in these types of power plants, the ambient conditions (temperature, humidity and pressure) are considered as important factors affecting their performance. The production capacity of gas turbines is rated by the International Standards Organization (ISO) which specified the following air inlet conditions as reference conditions: air temperature 15 o C (59 o F), relative humidity 60%, and absolute pressure (sea-level) 101.325kPa (14.7psia). Figure 2 shows that, as the temperature of air entering the compressor section of the gas turbine increases, the power output, thermal efficiency, and air mass flow rate decrease, while the heat rate increases in comparison with ISO rated values. The effect of ambient conditions on the performance of gas turbines has been discussed in various studies. De Sa and Al Zubaidy [3]considered specific gas turbines (SGT 94.2 and SGT 94.3) installed at the Dewa Power Station located at Al Aweer, Dubai. They investigated units performance at various ambient temperatures and concluded that for every 1 o C rise in ambient temperature above ISO conditions the units lose 0.1% in terms of thermal efficiency and 1.47 MW of gross (useful) power output. Ameri and Hejazi [4] reported that there are more than 170 gas turbine units in Iran with a combined capacity of 9500 MW. 20% of this capacity is lost during summer time. From the performance curves of the gas turbines, they concluded that for every 1 o C increase in ambient air temperature, the power output and the air mass flow rate will decrease by 0.74%and 0.36% respectively. Erdem and Sevilgen [5] studied the effect of ambient temperature on the electricity production and fuel consumption of two simple gas turbine models and seven climate regions in Turkey by using average monthly temperature data corresponding to those regions. They reported that electricity production loss occurs in all regions during the periods when the temperature is above 15 o C and loss rates vary between 1.67% and 7.22% depending on the regions. Electricity generation increases by 0.27 to 10.28% when inlet air is cooled to 10 o C. Al Ibrahim et al. [6] tested a simple gas cycle in the central Qaseem region of Saudi Arabia. They reported that a high mid-day ambient temperatures during summer can cause a 24% decrease in system capacity ...
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In the panorama of gas turbines for energy production, a great relevance is given to performance impact of the ambient conditions. Under the influence of ambient temperature, humidity and other factors, the engine performance is subject to consistent variations. This is true for large power plants as well as small engines. In Combined Cycle configu...
Citations
... Several researchers studied how the environment affects gas turbine performance. In the Kingdom of Saudi Arabia, where gas turbines produce more than 50% of the total capacity, Saleh et al., [28] examined the impact of ambient air conditions on gas turbine performance. In Ad Dammam, the ambient temperature can reach 45 o C, resulting in output power losses that can reach 16,139 kW. ...
The study focuses on estimating thermodynamic characteristics at constant pressure for ambient air as a working fluid for gas turbines. The objective of this paper is to carry out a thermodynamic analysis of the properties of air as a working gas for a power plant. Various values of relative humidity, as well as temperatures, were examined in this study. Code was written using EES (Engineering Equations Solver) to conduct the simulation. This code contains the necessary equation to compute the thermodynamic characteristics of the working fluid. According to the results, both temperature and relative humidity remarkably influence the specific heat capacity (C_p), isentropic exponent (γ_h) as well as the gas constant of air (R_h). According to the results, when the ambient air temperature is increased from 0 to 45 ℃ with constant relative humidity values of either 10% or 90%, the specific heat capacity increases by 5.01% and 17.6%, respectively. Furthermore, the isentropic exponent decreases by 1.07% and 4.5%, respectively. The results show that the gas constant of air increases with ambient air temperature and relative humidity. One can conclude that the ambient conditions have considerable influence on the thermodynamic characteristics of a gas turbine working fluid.
... When the gas has a larger volume, the compressor has to do more work to compress the gas into the same space, resulting in lower compressor efficiency. Therefore, in gas power plants, the air inlet temperature should be kept as low as possible to improve compressor efficiency [12]. One way to lower the air inlet temperature is by using a heat exchanger system, which can reduce the air inlet temperature before it enters the compressor. ...
This study aims to analyze the parameters that actively affect the efficiency of gas power plants in order to optimize their performance. The method used in this study was an analytical approach based on the results of performance tests conducted in 2018, 2020, and 2022 on gas power plants in the sumatera selatan area, based on thermodynamic equations. Based on the results of the study, it is explained that there is a very significant relationship between the inlet air temperature of the compressor, the inlet fuel temperature, and the turbine exhaust temperature and active power to the efficiency of gas-fired power plants, where an increase in the inlet air temperature to the compressor will reduce the compressor efficiency, which is predicted using linear regression with an R2=0.82. An increase in the exhaust temperature and active power will significantly reduce the thermal cycle efficiency, which is predicted using linear regression with an average R2 =0.96. In addition, an increase in the fuel mass flow rate and inlet fuel temperature will increase the turbine efficiency, which is predicted using linear regression with an average R2 =0.97. Therefore, the relationships obtained in this study can be used as a reference for energy companies and governments in developing more efficient gas-fired power plants in the future
... Baakeem et al. [13] studied typical and simple GT performance under Saudi weather conditions. The annual power production loss was 7.1%, 8.2%, and 11.2% in Riyadh, Ad Dammam, and Jeddah, respectively, due to variation in ambient conditions. ...
... (13):m air = 0.00891T 3 am − 0.80234 T 2 am + 20.92196T am + 470.73910(12)m NG = 4.09436*10 − 5 T 3 am − 3.61748*10 − 3 T 2 am + 3.27982*10 − 2 T am + 15.4240 ...
The enthalpy–entropy approach, which is a rigorous and accurate method, was used to model the actual cycle of a gas turbine (GT). The constructed GT C# programming language code was used to study the effects of ambient temperature (Tam), relative humidity (RH), and ambient pressure (Pam) on GT output parameters. The results of the GT modeling program showed that the maximum (minimum) difference in GT output power (PGT) was 1.12% (0.01%) at a Tam of 39.7 °C (23.3 °C) compared with the actual output power of El Atf power station. As Tam increased from 14 °C to 40 °C, the PGT decreased by 19.01% (18.38%) of nominal GT power (250 MW) at 15% (95%) RH while GT thermal efficiency (ηth) decreased by 2.3058% (2.4431%) and the specific fuel consumption (SFC) increased by 7.12% (7.59%). The PGT decreased by 0.1497% and 0.7674% with an RH increase from 15% to 95%, respectively. The PGT decreased by 0.03675 and 0.16835 MW while ηth decreased by 0.0047% and 0.0243% at Tam values of 15 and 40 °C, respectively, when Pam was decreased from 1.013 to 0.990 bar. Using the compressor assumptions of each stage increases the humid air pressure by the same value and the efficiency of each stage is the same and equal to the compressor overall efficiency is more logical and leads to accurate results. The compressor isentropic efficiency was not affected by the bleeding air percent according to the assumptions used.
... Gas turbine performance is notably affected by ambient air conditions. Several works studied the effect of ambient conditions on the performance of gas turbines (Al-Ibrahim et al., 2002;Al-Fahed et al., 2009;Ameri, M. and Hejazi, S., 2004;Baakeem et al., 2015;Baakeem et al., 2017;De Sa and Al Zubaidy, 2011;Erdem and Sevilgen, 2006). They concluded that the gas turbine performance decreases significantly when air temperature and humidity go to higher values. ...
This Book of Proceeding contains papers that were published in the 13th International Exergy, Energy, and Environment Symposium (IEEES13) during the conference time between 14-17 March 2022. The IEEES-13 brings outstanding keynote speakers coming from different backgrounds to address the evolving issues of energy, environment, and sustainable future. Furthermore, fellow researchers and scientists from over 30 countries will contribute to this symposium. This event, with participants from all over the world, represents the global commitment to resolving energy and environmental challenges such as global warming and climate change. It will also highlight scientific advances in many subjects, including Renewable Energy Technologies, Oil and Gas Technologies, Hydrogen production and Utilization, Smart Grid, and Green transportation.
... Gas turbine performance is notably affected by ambient air conditions. Several works studied the effect of ambient conditions on the performance of gas turbines (Al-Ibrahim et al., 2002;Al-Fahed et al., 2009;Ameri, M. and Hejazi, S., 2004;Baakeem et al., 2015;Baakeem et al., 2017;De Sa and Al Zubaidy, 2011;Erdem and Sevilgen, 2006). They concluded that the gas turbine performance decreases significantly when air temperature and humidity go to higher values. ...
The current work evaluates the performance of a gas turbine coupled with a mechanical vapor compression system under the arid ambient conditions of Riyadh, the capital of Saudi Arabia. Energy and exergy analyses of typical gas turbine and mechanical vapor compression systems are performed using the average hourly temperature and relative humidity. Three systems of mechanical vapor compression are evaluated. Those systems are simple mechanical vapor compression system, multistage mechanical vapor compression system with flash intercooling coupled with the dry air condenser (without cooling tower), and multistage mechanical vapor compression system with flash intercooling coupled with the wet air condenser (with cooling tower). Results indicate that the maximum exergy destructions of simple mechanical vapor compression system, multistage mechanical vapor compression system without cooling tower, and multistage mechanical vapor compression system with cooling tower are 3.7, 2.9, and 1.04 MW, respectively. The functional exergy efficiency of a gas turbine coupled with the cooling is approximately constant and higher than that without a cooling unit.
... From • Accordingly, ∆ = 10 °C • F represented the correction factor for the average mean temperature difference, its value ranges given (1-0.8) [16]depending on two temperature ratios P and R that equal 0.952 [27]. ...
... Effect of inlet ambient temperature on the gas turbine performance[16].East 35 o11'43.27'' North 44o96'67.62'' ...
The study aims tray to improve the performance of the Al-Mansourieh gas power plant located in Iraq with a production (4 ×732 MW). By proposing a new (cooling/heating) system for air that entering the compressor by using groundwater (well water) as a renewable energy. FCU-Unit system operates according to the annual season. The calculations for the study was carried out in two stages, the first one included the thermodynamic analysis of the proposed system and finding the optimal design of space for heat exchanger. By another calculation, the amount of cooling water it was between (14.5-87) kg / s and the rate of airflow that reached (1.87m3/h). While the second part of this study included calculating the ideal and actual efficiency through the introduction of the actual conditions for the work of the turbine which took into account the pressure losses in the turbine inlet, exhaust pressure losses, combustion chamber pressure losses, combustion efficiency, and compressor and turbine efficiencies. Analytical results showed that heat efficiency and net capacity decrease in proportional to increasing air temperature. While the quantity of specific fuel consumed and the average heat increasing too with increasing air temperature. There for this study encouraging strongly that considering the air cooling before entering the combustion to improve the efficiency.
... Fuel efficiency of combustion engines (gas turbines [1][2][3], diesel engines [4] and gas engines [5][6][7]) falls with raising an ambient air temperature at their intake. Gas turbines (GT) are especially sensitive to intake conditions [8][9][10]: a specific fuel consumption increases by 0.4 to 1.0 g/(kWh) for every 1K rise Many modern methods of analyses [58][59][60] are aimed to increase the effect gained due to ambient air processing, in particular, to reduce energy and fuel consumption. Some of such methods include calculation of cooling degree-hours (CDH) [14,61] and modified versions [62][63][64] to match current cooling duties according to actual climatic conditions as well as thermal demand management (TDM) [65,66] based on different criteria [67,68] to save energy in building conditioning, engine intake air cooling and combined cooling, heat and power. ...
The efficiency of cooling ambient air at the inlet of gas turbines in temperate climatic conditions was analyzed and reserves for its enhancing through deep cooling were revealed. A method of logical analysis of the actual operation efficiency of turbine intake air cooling systems in real varying environment, supplemented by the simplest numerical simulation was used to synthesize new solutions. As a result, a novel trend in engine intake air cooling to 7 or 10 °C in temperate climatic conditions by two-stage cooling in chillers of combined type, providing an annual fuel saving of practically 50%, surpasses its value gained due to traditional air cooling to about 15 °C in absorption lithium-bromide chiller of a simple cycle, and is proposed. On analyzing the actual efficiency of turbine intake air cooling system, the current changes in thermal loads on the system in response to varying ambient air parameters were taken into account and annual fuel reduction was considered to be a primary criterion, as an example. The improved methodology of the engine intake air cooling system designing based on the annual effect due to cooling was developed. It involves determining the optimal value of cooling capacity, providing the minimum system sizes at maximum rate of annual effect increment, and its rational value, providing a close to maximum annual effect without system oversizing at the second maximum rate of annual effect increment within the range beyond the first maximum rate. The rational value of design cooling capacity provides practically the maximum annual fuel saving but with the sizes of cooling systems reduced by 15 to 20% due to the correspondingly reduced design cooling capacity of the systems as compared with their values defined by traditional designing focused to cover current peaked short-term thermal loads. The optimal value of cooling capacity providing the minimum sizes of cooling system is very reasonable for applying the energy saving technologies, for instance, based on the thermal storage with accumulating excessive (not consumed) cooling capacities at lowered current thermal loads to cover the peak loads. The application of developed methodology enables revealing the thermal potential for enhancing the efficiency of any combustion engine (gas turbines and engines, internal combustion engines, etc.).
... The production capacity of gas turbines is rated by the International Standards Organization (ISO), which specified the following reference air inlet conditions: air 15°C (59°F), relative humidity 60% and absolute pressure (sea-level) 101.325 kPa (14.7 psia). Several studies have discussed the effect of ambient conditions on the performance of gas turbines [6][7][8][9][10][11][12]. De Sa and Al Zubaidy [8] studied gas turbine performance at varying ambient temperature for specific turbines SGT 94.2 and SGT 94.3 installed at the Dewa Power Station located at Al Aweer, H Phase II and III in Dubai, UAE. ...
... They reported that a high mid-day ambient temperature during the summer can cause a 24% decrease in system capacity [1]. Baakeem et al. [11] studied theoretically the effect of the average hourly temperature and relative humidity on the performance of a typical gas turbine unit used in three Saudi regions: Dammam, Riyadh, and Jeddah. The obtained results showed that both ambient temperature and humidity have significant effects on the gas turbine performance. ...
... The ISO conditions are taken as dead state conditions. The authors [11,12] concluded that adding inlet cooling systems to the existing gas turbine units should be considered seriously and could be justified in hot periods. ...
Gas turbine performance is very sensitive to the ambient air conditions, particularly in hot and arid climates. Various turbine inlet air cooling (TIAC) techniques including mechanical vapor compression and lithium bromide-water absorption refrigeration systems are used in several locations worldwide. This work concerns a comparative study using mass and energy balances and cost analysis of several cooling technologies coupled with a typical gas turbine under Riyadh weather conditions. The results are expressed in terms of yearly variations of power output, fuel consumption, and thermal efficiency of the gas turbine unit. They also include the total and operating costs and the payback period for each configuration of TIAC systems. The study proposes first systematic approaches to determine the air cooled temperature at the compressor inlet and the corresponding cooling capacity for the considered TIAC systems. The optimum values of such air cooled temperature and cooling capacity are found to be 8 °C and 36 kW/m³ s⁻¹, respectively. The comparative study shows that using the media evaporative cooling, the simple mechanical vapor compression or the single-effect H2O-NH3 absorption cooling systems are not recommended. However, the sub-cooling multistage compressor system coupled with a wet cooled condenser and the single-effect LiBr-H2O-absorption refrigeration systems show better performance.
... They concluded that high ambient temperatures of mid-day of the summer season cause a 24% decreasing in system capacity [10]. Baakeem et al. [11] studied theoretically the effect of the average hourly temperature and relative humidity on the performance of a typical gas turbine unit used in three Saudi regions: Ad Dammam, Riyadh and Jeddah. The obtained results showed that both ambient temperature and humidity have a significant effect on the gas turbine performance. ...
... It is of interest to mention that the above governing equations are based on mass, energy and exergy balances for the whole gas turbine unit and its main components under steady-state conditions. Such an approach has been widely used in similar previous works (see, for instance, [8,[11][12][13][14]19,22,26]). It is assumed the changes in the ambient conditions and their effect on the gas turbine performance and components parameters would not affect the steady-state behavior of the power system. ...
In this paper, energy and exergy analysis of typical gas turbines is performed using average hourly temperature and relative humidity for selected Gulf cities located in Saudi Arabia, Kuwait, United Arab Emirates, Oman, Bahrain and Qatar. A typical gas turbine unit of 42 MW is considered in this study. The electricity production, thermal efficiency, fuel consumption differences between the ISO conditions and actual conditions are determined for each city. The exergy efficiency and exergy destruction rates for the gas turbine unit and its components are also evaluated taking ISO conditions as reference conditions. The results indicate that the electricity production losses occur in all cities during the year except in Dammam and Kuwait for the period between November and March. During the hot period extended from April to September, the power losses vary between 2 MW to about 9 MW. During a typical day, the variation of the power production can reach 4 MW. The maximum power gain ranges from 4 and 6% of the ISO power at temperatures of 9.9 and 7.9°C in January for Dammam and Kuwait, respectively. The annual power loss ranges between 8.7 and 11.2% of the ISO annual power and the maximum annual loss occurs in Dubai and Muscat. The relative drop in the fuel consumption ranges between 7.6 and 9%. The rate of exergy destruction under the combined effect of temperature and humidity is significant in hot months reaching a maximum of 12 MW in July. It decreases as the ambient temperature increases but increases as the relative humidity increases. The presented results show also that adding inlet cooling systems to the existing gas turbine units could be justified in hot periods. The economic and environmental aspects should also be investigated.
Keywords: Gas turbine performance; arid ambient conditions; electric power generation; fuel consumption; exergy analysis.
... 3 Many studies have focused on various methods for cooling the compressor's inlet air. Baakeem et al. 4 theoretically investigated the influence of temperature and relative humidity on the performance of a typical gas turbine unit. They found that both parameters, that is, ambient temperature and humidity, significantly reduced the gas turbine performance. ...
Gas–steam combined cycle power plants are the most efficient electricity‐generation units based on fossil fuels. However, these power plants are prone to efficiency decrease in hot climates as high ambient temperatures adversely influence the gas turbine's output. The present study investigated the effect of incorporating a solar absorption refrigeration (SAR) system into an actual combined cycle power plant for the first time. First, the energy and exergy analyses were performed using THERMOFLOW software. Then, the influence of the ambient temperature (10°C–52.5°C) on the power plant's performance and its components was investigated. The SAR system was then used to cool the compressor's input air and improve the power generation capacity by employing TRNSYS software. The results showed that the power plant reached its maximum efficiency at an ambient temperature of 26.6°C. However, its overall efficiency and net power generation were dropped with a further increase in the ambient temperature. Employing the SAR system for each gas turbine in the power plant on a sunny day until 2 p.m. would decrease the compressor's input air temperature. For example, for the refrigeration capacities of 450, 700, and 1000 tons for each gas turbine, the temperature was reduced by nearly 3°C, 5°C, and 7°C, respectively. Under the same condition, power generation capacity improved by 12.5, 24, and 32.5 MW, and the overall efficiency rose by 0.6%, 1.4%, and 2%. Such an increase in power and efficiency occurred during peak demand, which was significant.
