Inlet Air Cooling System Research Articles

A novel inlet air cooling system to improve the performance of intercooled gas turbine combined cycle power plants in hot regions

In hot climates, the entry of high-temperature air into the compressor of intercooled gas turbine power plants (IcGTCC) can lead to reduced electricity production during peak demand periods. To address this issue, this study proposes a novel inlet air cooling (IAC) system for improving the performance of IcGTCC in hot regions. This system utilizes waste heat from the intercooler to cool the compressor's inlet air via absorption chillers. The performance of this system was evaluated and compared to four popular IAC technologies: evaporative cooling, solar-powered absorption cooling, steam-operated absorption cooling, and vapor compression cooling. Additionally, the expected annual profit and payback period were estimated. Results show that the proposed IAC system resolves the drawbacks of IcGTCC in hot regions, increasing the power output by 19% and the overall efficiency by 2.3%. It is estimated that the proposed IAC system can improve plant efficiency by 8–18% compared to literature designs, leading to higher annual profits (66% and 10% higher than steam and mechanical cooling systems, respectively). Moreover, it has a short payback period of 1.74 years, which is 3%, 67%, and 85% shorter than mechanical, steam, and solar cooling systems, respectively, making it a highly cost-effective solution.

Technical and Economic Feasibility Analysis of Solar Inlet Air Cooling Systems for Combined Cycle Power Plants

In this study, the thermodynamic behavior of a combined cycle power plant with integrated solar-driven inlet air cooling was simulated for Tehran, Phoenix, and Houston during warm-hot seasons. A considerable reduction in the output power was realized during hot ambient conditions due to the lower density of the air and lower mass flow rate to the turbines. The output power decreases from 306.6 to 260.8 MW as ambient temperature increases from 15 to 45 °C. This research focuses on utilizing solar cooling systems to achieve low inlet air temperature to generate high-electricity yields. Four different types of solar collectors and two different absorption chiller units were selected and simulated for each city to achieve the required goal. It was identified that integrating a solar inlet air cooling (SIAC) system can avert the reduction in output power with no impact on efficiency. The humid climatic condition in Houston and the low electricity cost in Tehran posed some challenges in designing a feasible SIAC system. However, by optimizing the solar collectors and cooling capacities, an optimal solution for utilizing inlet air cooling in humid climates is presented. In terms of overall impact, the evacuated flat plate collector (EFPC) coupled with a double-effect absorption chiller displayed the best economic performance among the four variants under study. In Phoenix, this combination can maintain output power during hot days with a DPR of 2.96 years.

Computer Aided Intelligent Control of Inlet Air Cooling System in Combined Cycle Power Plant

In hot climate, the overall efficiency of combined cycle power plant (CCPP) decreases dramatically owing to the rise of environment temperature, which decreases the mass air flow to the compressor. Therefore, the gross power and thermal efficiency drop. Worldwide practice uncovers that gas turbines generate up to 20% less power in summer than in winter. A brief introduction of the CCPP and analysis of influence of ambient temperature are provided in this work. Furthermore, this essay gives a outline of the combined cycle based on several inlet air cooling technologies and why they are necessary. Since 1987, more and more inlet air cooling systems have been devised, each of which has its own advantages and limitations. They are mainly divided into 2 classes. Low cost and ease of operation are the main advantages of evaporation systems. However, they are strictly restricted by the wet-bulb temperature. In terms of the mechanical systems, which are not limited to it, command high initial and operating cost. The absorption chiller utilizes the waste heat of exhaust gases, which means they have great potential. In the end, economic criteria and problems to be solved are mentioned.

Technical and Economic Evaluation of Solar Inlet Air Cooling Systems for Combined Cycle Power Plants

Technical and Economic Evaluation of Solar Inlet Air Cooling Systems for Combined Cycle Power Plants

Exergetic and Exergoeconomic Optimization of Gas Turbine Inlet Air Cooling Systems with Absorption or Compression Chilling

The present paper aims to study the effect of cooling air inlet methods on gas turbine compressors on increasing their efficiency. After modeling gas turbine cycles with absorption and compression systems in the EES software, these cycles' performance is investigated for all equipment of the cycle from thermodynamic, exergy, and exergoeconomic aspects. In the absorption system, the conventional solution of lithium bromide-water is used as a two-component fluid, and in the compression cycle, the R134a operating fluid is used. According to the results, with the rise in the system's inlet air temperature, the total output work of the gas turbine decreases. Based on the exergoeconomic analysis, the exergy destruction cost dominates the initial cost, resulting in the exergoeconomic factor's decline. Relationship predicted by Group Method of Data Handling (GMDH) to reduce the computation time of optimization. The studied systems are then subjected to two-objective optimization by the Particle Swarm algorithm using MATLAB software. The objective functions are related to the exergy efficiency and total cost rate. The results reveal contradictory behavior in these two objective functions so that with the increase in the exergy efficiency, the total cost rate increases.

Augmentation of gas turbine performance using integrated EAHE and Fogging Inlet Air Cooling System

In the present work, new hybrid cooling system is demonstrated and compared with other configurations of gas turbine inlet air-cooling systems. The cooling configurations include the earth-air heat exchanger, fogging and a new hybrid cooling system. Three models are developed, the first is for prediction of the cooling potential of the fogging system and the second is based on the transient one-dimensional heat transfer modeling which is used to describe the thermal behavior of the earth-air heat exchanger. The third model is a combination of earth-air heat exchanger and fogging cooling system as a new hybrid cooling system. New Damietta power plant located in the coastal region in Egypt (Latitude = 31.4 and Longitude = 31.7) is applied as a case study. A comparison between the effects of the three air cooling techniques on the gas turbine performance was performed. It is observed that the hybrid system is superior to the unitary systems as it is capable of boosting the average annual energy by 9.8% versus 8 and 6.6% for fogging and earth-air heat exchanger system; respectively. In addition, the hybrid system reduces the water consumption by 50% compared to the fogging system. Moreover, the hybrid cooling system is the most efficient method in the areas where the temperature is over 30°C and the relative humidity is less than 60%.

Feasibility Study of Turbine Inlet Air Cooling using Mechanical Chillers in Malaysia Climate

The performance of a gas turbine is dependent on the ambient air temperature. The gas turbine’s power output is reduced and heat rate is increased as a result of higher air temperature. The warm and humid climate in Malaysia, with its high ambient air temperature, has an adverse effect on the performance of gas turbine generators. Turbine Inlet Air Cooling is a power augmentation technology for gas turbines, which reduces the turbine inlet air temperature thereby improving the power output and heat rate of the machine. In this paper the effect of Turbine Inlet Air Cooling using electric chillers, on the performance of the LM6000PD Gas Turbine Generator (43.5MW ISO rating) is evaluated in the context of the Malaysian climate. GT Pro software is used to evaluate the performance of the gas turbine generator with ambient air temperature cooled to 12°C. The ambient design points used for the sizing of the chillers are the 0.4% Evaporative (Design Point A) and the 0.4% Cooling (Design Point B) design points for Sitiawan, Perak as published by ASHRAE. It is observed that Design Point A results in a chiller capacity of 1950RT which is sufficient to satisfy the cooling demand of the Turbine Inlet Air Cooling system for approximately 98% of the operating hours in a year, while Design Point B yields a smaller chiller size of 1700RT which is capable of meeting the Turbine Inlet Air Cooling requirement for approximately 72% of the annual operating hours. In terms of Gas Turbine performance, the net power output is increased by 27.5% and 32.11% while the net heat rate is reduced by 2.8% and 3.74% for Design Points A and B respectively. The substantial improvement in gas turbine net power output and heat rate as predicted by the GT Pro demonstrate that Turbine Inlet Air Cooling using electric chillers is effective as a power augmentation technology in Malaysia.

Exergy Analysis of a Novel Inlet Air Cooling System with gas Turbine Engines using cascaded Waste-heat Recovery

In this work, an innovative sustainable energy efficient system is dealt with cascaded waste-heat recovery system (CWHRS). It is composed of a gas turbine (GT) engine, where the heat was recovered from exhaust gases in an upper propane ORC cycle which produces power from the first expander. This heat is further recovered in another lower propane gas refrigeration cycle, where the most important target is cooling the ambient intake air of the GT engine. Thus, engine power is boosted and thermal efficiency is improved. An exergy analysis is carried out, where the primary objective is to analyse each component and overall system, hence determining where the major losses of exergy occur. Many operating variables are taken into consideration: namely, inlet temperature of expander 1, turbine inlet temperature, pressure ratio for the GT, upper and lower propane cycles. The analysis shows that at design point the overall exergy efficiency and destruction are 37% and 95,952 kW, respectively. Moreover, the highest amount of irreversibility occurs in the combustion chamber due to the high temperature difference in the chemical reaction. The optimisation analysis reveals best exergy efficiency with about 40%.

Parametric Simulation on Enhancement of the Regenerative Gas Turbine Performance by Effect of Inlet Air Cooling System and Steam Injection

Iraq being one of the developing countries of the world considers energy efficiency and the impact of its generation on the environment an imperative process in improvement of its power generation policies. Iraq bearing high temperatures all year long results in reduction of air density, therefore, Inlet air Cooling and Steam Injection Gas Turbines are a striking addition to the regenerative gas turbines. Regenerating Gas turbines tend to have a high back work ratio and a high exhaust temperature, thus, it leads to a low efficiency in power generation in hotter climate. Moreover, STIG and IAC through fog cooling have known to be the best retrofitting methods available in the industry which improve the efficiency of generation from 30.5 to 43% and increase the power output from 22MW to 33.5MW as the outcomes of computer simulations reveal. Additionally, this happens without bringing about much extensive change to original features of the power generation cycle. Furthermore, STIG and spray coolers have also resulted in power boosting and exceeding generation efficiency of gas turbine power plant.

Analysis of parameters affecting the performance of gas turbines and combined cycle plants with vapor absorption inlet air cooling

SUMMARY The integration of an aqua-ammonia inlet air-cooling scheme to a cooled gas turbine-based combined cycle has been analyzed. The heat energy of the exhaust gas prior to the exit of the heat recovery steam generator has been chosen to power the inlet air-cooling system. Dual pressure reheat heat recovery steam generator is chosen as the combined cycle configuration. Air film cooling has been adopted as the cooling technique for gas turbine blades. A parametric study of the effect of compressor–pressure ratio, compressor inlet temperature, turbine inlet temperature, ambient relative humidity, and ambient temperature on performance parameters of plants has been carried out. It has been observed that vapor absorption inlet air cooling improves the efficiency of gas turbine by upto 7.48% and specific work by more than 18%, respectively. However, on the adoption of this scheme for combined cycles, the plant efficiency has been observed to be adversely affected, although the addition of absorption inlet air cooling results in an increase in plant output by more than 7%. The optimum value of compressor inlet temperature for maximum specific work output has been observed to be 25 °C for the chosen set of conditions. Further reduction of compressor inlet temperature below this optimum value has been observed to adversely affect plant efficiency. Copyright © 2013 John Wiley & Sons, Ltd.

Measurement and Control of the Gas Turbine Inlet Air Cooling System

As a constant-column power generating machine, the combustion turbine has a direct proportion of its output to the quantity of input air. Therefore, when the ambient air temperature rises higher in summer, the effect of combustion turbine is decreasing. In order to enhance the efficiency of combustion turbine in summer, two sets of inlet air cooling system (IACS) were installed in PG6551(B) combustion turbines in Jinhua, Zhejiang, China. Two low-pressure evaporators were installed in the caudal flue of the waste heat boiler, therefore, the produced saturation steam drives a single-effect lithium bromide absorption chiller to cool the input air of combustion turbines to raise the output power of combustion turbine in summer; or supplies the low-pressure heater to heat the condensated water from the deaerator of the steam turbine in winter. A measurement and control system (MCS) of the new-added inlet air cooling equipments was developed. Based on the framework of DCS (Distributed Computer System), the M&C system has the IACS work correctly and easily. The structure and functions of the M&C is described in detail.

Performance and sensitivity analysis of a combined cycle gas turbine power plant by various inlet air-cooling systems

This article is aimed at carrying out a performance analysis of a combined cycle gas turbine power plant with various inlet air-cooling systems. A comparison is performed using different cooling systems, including evaporative cooling, fogging, mechanical (electric) chiller cooling, and absorption cooling. A performance analysis is completed for each system. The performance characteristics are determined for a set of actual operational parameters including ambient conditions (temperature and relative humidity), turbine inlet temperature, pressure ratio, etc. To evaluate the net power output and efficiency for each system, a combined cycle unit system consisting of inlet air cooling system, gas turbine, dual pressure heat recovery steam generators, and steam turbine has been analyzed. The results show that power and efficiency improvements depend on ambient air temperature. In addition, by decreasing the ambient temperature and increasing the humidity of the air, the output power can be increased. The carbon dioxide emissions for each cooling system are also discussed. The results and the sensitivity analysis show that the absorption cooling system is most effective.

Exergy, economic and environment (3E) analysis of absorption chiller inlet air cooler used in gas turbine power plants

Gas turbine (GT) output power is affected by temperature, gas turbine inlet air-cooling systems are used to solve this. In the present work, the effect of using absorption chiller in GT power plants for two regions in Iran, namely Tabas with hot–dry and Bushehr with hot–humid climate conditions is conducted. Therefore, output power, first and second law efficiencies, environmental and electrical costs for GT power plant with inlet air cooler are calculated for two mentioned regions, respectively. Results show that using this system in hot months of a year is economical. In addition, using absorption chiller leads to increasing the output power 11.5 and 10.3%, for Tabas and Bushehr cities, respectively. Moreover, by using this method the second law efficiency is increased to 22.9 and 29.4% for Tabas and Bushehr cities, respectively. In addition, the cost of electricity production for Tabas and Bushehr cities decreases to about 5.04 and 2.97%, respectively. Copyright © 2011 John Wiley & Sons, Ltd.

Systematic Assessment of Combustion Turbine Inlet Air-Cooling Techniques

The current study is centered on assessing the benefits of incorporating combustion turbine inlet air-cooling systems into a reference combustion turbine plant, which is based on a simple cycle under base load mode. Actual climatic conditions of a selected site were examined thoroughly to identify the different governing weather patterns. The main performance characteristics of both refrigerative and evaporative cooling systems were explored by examining the effect of several parameters including inlet air temperature, airflow-to-turbine output ratio, coefficient of performance (for refrigerative cooling systems), and evaporative degree hours (for evaporative cooling systems). The impact of these parameters was presented against the annual gross energy increase, average heat rate reduction, cooling load requirements and net power increase. Finally, a feasibility design chart was constructed to outline the economic returns of employing a refrigerative cooling unit against different prescribed inlet air temperature values using a wide range of combustion turbine mass flow rates.