Gas Turbine Performance Enhancement by Inlet Air Cooling and Coolant Pre-Cooling Using an Absorption Chiller

2016 ◽  
Author(s):  
Hyun Min Kwon ◽  
Jeong Ho Kim ◽  
Tong Seop Kim
Keyword(s):  
Gas Turbine ◽  
Air Temperature ◽  
Power Plants ◽  
Cooling System ◽  
Combined Cycle ◽  
Air Cooling ◽  
Absorption Chiller ◽  
Large Power ◽  
Cycle Simulation ◽  
Standard Design

The gas turbine combined cycle is the most mature and efficient power generation system. While enhancing design performance continuously, a parallel effort to make up for the shortcomings of the gas turbine should be pursued. The most critical drawback is the large power loss in hot season when electricity demand is usually the highest. Therefore, it is important to implement an effective power boosting measure in gas turbine based power plants, especially in areas where the annual average temperature is much higher than the standard design ambient temperature. The simplest method in general is to reduce the gas turbine inlet air temperature by any means. Several schemes are commercially available, such as mechanical chilling, evaporative cooling, inlet fogging and absorption chilling. All of them have merits and demerits, either thermodynamically and economically. In this study, we focused our interest on the absorption chilling method. Theoretically, absorption chilling provides as much cooling effect (air temperature reduction) as the mechanical chilling, while electric power consumption is negligibly small. A distinct feature of an absorption chiller in contrast to a mechanical chiller is that thermal energy (heat) is needed to drive the chilling system. In this research, we propose an innovative idea of making the independent heat supply unnecessary. The new method provides simultaneous cooling of the turbine coolant and the inlet air using an absorption chiller. The inlet cooling and coolant precooling boost the gas turbine power synergistically. We predicted the system performance using cycle simulation and compared it with that of the conventional mechanical cooling system.

An Innovative Inlet Air Cooling System for IGCC Power Augmentation: Part II—Thermodynamic Analysis

2012 ◽  
Author(s):  
Mirko Morini ◽  
Michele Pinelli ◽  
Pier Ruggero Spina
Keyword(s):  
Gas Turbine ◽  
Air Temperature ◽  
Power Plants ◽  
Cooling System ◽  
Ambient Air ◽  
Combined Cycle ◽  
Air Separation ◽  
Air Cooling ◽  
Separation Unit ◽  
Gasification Process

Integrated Gasification Combined Cycles (IGCCs) are energy systems mainly composed of a gasifier and a combined cycle power plant. Since the gasification process usually requires oxygen as the oxidant, the plant also has an Air Separation Unit (ASU). Moreover, a producer gas cleaner unit is always present between the gasifier and the gas turbine. Since these plants are based on gas-steam combined cycle power plants they suffer from a reduction in performance when ambient temperature increases. In this paper, an innovative system for power augmentation in IGCC plants is presented. The system is based on gas turbine inlet air cooling by means of liquid nitrogen spray. In fact, nitrogen is a product of the ASU, but is not always exploited. In the proposed plant, the nitrogen is first chilled and liquefied and then it can be used for inlet air cooling or stored for a postponed use. This system is not characterized by the limits of water evaporative cooling (where the lower temperature is limited by air saturation) and refrigeration cooling (where the effectiveness is limited by pressure drop in the heat exchanger). A thermodynamic model of the system is built by using a commercial code for the simulation of energy conversion systems. A sensitivity analysis on the main parameters (e.g. ambient air temperature, inlet air temperature difference, etc.) is presented. Finally the model is used to study the capabilities of the system by imposing the real temperature profiles of different sites for a whole year.

Effect of Inlet Air Cooling by Absorption Chiller on Gas Turbine and Combined Cycle Performance

2005 ◽  
Author(s):  
Hiwa Khaledi ◽  
Roozbeh Zomorodian ◽  
Mohammad Bagher Ghofrani
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Cooling System ◽  
Positive Influence ◽  
Combined Cycle ◽  
Cycle Performance ◽  
Air Cooling ◽  
Internal Source ◽  
Absorption Chiller

Gas turbine performances are directly related to site conditions. The use of gas turbines in combined gas-steam power plants, also applied to cogeneration, increases such dependence. In recent years, inlet air cooling systems have been introduced to control air temperature at compressor inlet, resulting in an increase in plant power and efficiency. In this paper, the dependence of outside conditions for a simple gas turbine and a combined cycle plant is studied, using absorption chiller as inlet air cooling system. We used, as case study, a simple plant equipped with one frame E gas turbine and a combined cycle with a two pressure level heat recovery steam generator (HRSG). It was found that inlet air cooling with absorption chiller has great positive influence on power and less on efficiency of the gas turbine plant. Two steam sources (External and Internal) have been considered for chiller. External source has large positive influence on power but keep the efficiency of the combined cycle unchanged, while internal source causes a reduction in steam turbine mass flow. Consequently power production and efficiency of the combined cycle decrease. This reduction is lower in mid temperature (25 to 35°C) but higher in high temperature (35 to 45°C). Inlet cooling would result in lowering turbine exhaust temperature, thus decreasing the efficiency of HRSG.

Technical and Economical Evaluation of Media and Fog Systems in Fars, Qom, Yazd, Shahid Rajaee Power Plants

2012 ◽  
Vol 433-440 ◽  
pp. 7229-7233
Author(s):  
Karim Maghsoudi Mehraban ◽  
Seyyed Vahid Mahmoodi Jezeh ◽  
Seyyed Hossein Musa Kazemi
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Air Temperature ◽  
Power Plants ◽  
Cooling System ◽  
Combined Cycle ◽  
Power House ◽  
Economical Evaluation ◽  
Hot Days ◽  
Media Systems

In the hot days of summer, the efficiency of gas turbine is extremely reduced because the input air to compressors becomes hot. For solving this problem, one can increase the efficiency of the power house by charging to decrease the input air temperature to the compressor of gas turbine. In this paper, all kinds of cooling the inlet air to the gas turbine are introduced and then the technical and economical evaluation of these installed cooling system in Shahid Rajaee, Qom, Fars and Yazd power plants are expressed and the results show that the fog system cannot prove its effectiveness in Shahid Rajaee and Qom power plants. Whereas the installation of media systems in Fars combined cycle power plant produces more megawatt than its guarantee conditions and no particular problem has been observed.

GT Inlet Air Boosting and Cooling Coupled With Cold Thermal Storage in Combined Cycle Power Plants

2008 ◽  
Author(s):  
Nicola Palestra ◽  
Giovanna Barigozzi ◽  
Antonio Perdichizzi
Keyword(s):  
Gas Turbine ◽  
Energy Production ◽  
Power Plants ◽  
Cooling System ◽  
Electric Energy ◽  
Thermal Storage ◽  
Combined Cycle ◽  
Inlet Pressure ◽  
Air Cooling ◽  
Air Cooling System

Investigation results of compressor inlet air boosting and cooling, applied to combined cycle power plants, are presented and discussed. Gas turbine performances may be reduced by site altitude and inlet losses due to air ducts and filters. Increasing inlet pressure by fans allows the restoring of gas turbine power output and efficiency at least to ISO reference conditions. Coupling such a system with inlet air cooling may completely suppress the temperature increase given by inlet air compression and the pressure losses through air coils as well; therefore, by this way, a further increase of electric energy production can be achieved. An in-house simulation code, developed for evaluating inlet air cooling system performance by cool thermal storage, has been adapted in order to also simulate off-design behaviour of boosting applied to combined cycle plants. A 127 MW reference power plant, operating in the Italian scenario, has been considered. Inlet pressure increase has been evaluated with and without inlet cooling, and in comparison with inlet cooling solution alone. Both thermodynamic and economical results have been analyzed. A parametric analysis on both system sizing parameters has been carried out. Best solution was found in coupling boosting to inlet cooling system through cool thermal storage; it produced an important increase in electric energy production. Location site influence on investment pay-back proved to be less important compared to the solution with inlet air cooling system alone.

Optimization of fog inlet air cooling system for combined cycle power plants using genetic algorithm

2015 ◽  
Vol 76 ◽  
pp. 449-461 ◽  
Author(s):  
Mehdi A. Ehyaei ◽  
Mojtaba Tahani ◽  
Pouria Ahmadi ◽  
Mohammad Esfandiari
Keyword(s):  
Genetic Algorithm ◽  
Power Plants ◽  
Cooling System ◽  
Combined Cycle ◽  
Air Cooling ◽  
Air Cooling System

Inlet Air Cooling Applied to Combined Cycle Power Plants: Influence of Site Climate and Thermal Storage Systems

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Nicola Palestra ◽  
Giovanna Barigozzi ◽  
Antonio Perdichizzi
Keyword(s):  
Power Output ◽  
Parametric Analysis ◽  
Power Plants ◽  
Cooling System ◽  
Thermal Storage ◽  
Combined Cycle ◽  
Operating Conditions ◽  
Air Cooling ◽  
Ambient Conditions ◽  
Cooling Systems

The paper presents the results of an investigation on inlet air cooling systems based on cool thermal storage, applied to combined cycle power plants. Such systems provide a significant increase of electric energy production in the peak hours; the charge of the cool thermal storage is performed instead during the night time. The inlet air cooling system also allows the plant to reduce power output dependence on ambient conditions. A 127MW combined cycle power plant operating in the Italian scenario is the object of this investigation. Two different technologies for cool thermal storage have been considered: ice harvester and stratified chilled water. To evaluate the performance of the combined cycle under different operating conditions, inlet cooling systems have been simulated with an in-house developed computational code. An economical analysis has been then performed. Different plant location sites have been considered, with the purpose to weigh up the influence of climatic conditions. Finally, a parametric analysis has been carried out in order to investigate how a variation of the thermal storage size affects the combined cycle performances and the investment profitability. It was found that both cool thermal storage technologies considered perform similarly in terms of gross extra production of energy. Despite this, the ice harvester shows higher parasitic load due to chillers consumptions. Warmer climates of the plant site resulted in a greater increase in the amount of operational hours than power output augmentation; investment profitability is different as well. Results of parametric analysis showed how important the size of inlet cooling storage may be for economical results.

Comparative Analysis of Different Inlet Air Cooling Technologies Including Solar Energy to Boost Gas Turbine Combined Cycles in Hot Regions

2018 ◽  
Vol 140 (11) ◽  
Author(s):  
Ahmed Abdel Rahman ◽  
Esmail M. A. Mokheimer
Keyword(s):  
Comparative Analysis ◽  
Gas Turbine ◽  
Output Power ◽  
Power Output ◽  
Combined Cycle ◽  
Air Cooling ◽  
Absorption Chiller ◽  
Absorption Chillers ◽  
Combined Cycles ◽  
Net Power Output

Cooling the air before entering the compressor of a gas turbine of combined cycle power plants is an effective method to boost the output power of the combined cycles in hot regions. This paper presents a comparative analysis for the effect of different air cooling technologies on increasing the output power of a combined cycle. It also presents a novel system of cooling the gas turbine inlet air using a solar-assisted absorption chiller. The effect of ambient air temperature and relative humidity on the output power is investigated and reported. The study revealed that at the design hour under the hot weather conditions, the total net power output of the plant drops from 268 MW to 226 MW at 48 °C (15.5% drop). The increase in the power output using fogging and evaporative cooling is less than that obtained with chillers since their ability to cool down the air is limited by the wet-bulb temperature. Integrating conventional and solar-assisted absorption chillers increased the net power output of the combined cycle by about 35 MW and 38 MW, respectively. Average and hourly performance during typical days have been conducted and presented. The plants without air inlet cooling system show higher carbon emissions (0.73 kg CO2/kWh) compared to the plant integrated with conventional and solar-assisted absorption chillers (0.509 kg CO2/kWh) and (0.508 kg CO2/kWh), respectively. Also, integrating a conventional absorption chiller shows the lowest capital cost and levelized electricity cost (LEC).

scholarly journals Thermal and Economic Analysis of Gas Turbine Using Inlet Air Cooling System

2018 ◽  
Vol 225 ◽  
pp. 01020
Author(s):  
Thamir K. Ibrahim ◽  
Mohammed K. Mohammed ◽  
Omar I. Awad ◽  
Rizalman Mamat ◽  
M. Kh Abdolbaqi
Keyword(s):  
Life Cycle ◽  
Power Systems ◽  
Gas Turbine ◽  
Life Cycle Cost ◽  
Power Plants ◽  
Cooling System ◽  
Air Cooling ◽  
Air Cooling System ◽  
Cooling Mechanism ◽  
Cooling Loads

A basic goal of operation management is to successfully complete the life cycle of power systems, with optimum output against minimal input. This document intends calculating both, the performance and the life cycle cost of a gas turbine fitted with an inlet air cooling mechanism. Correspondingly, both a thermodynamic and an economic model are drawn up, to present options towards computing the cooling loads and the life cycle costs. The primary observations indicate that around 120MWh of power is derived from gas turbine power plants incorporating the cooling mechanism, compared to 96.6 MWh for units without the mechanism, while the life cycle cost is lower for units incorporating the cooling process. This indicates benefits in having the mechanism incorporated in the architecture of a gas turbine.

Performance Assessment of Steam Injection Gas Turbine With Inlet Air Cooling

1997 ◽  
Author(s):  
Carlo M. Bartolini ◽  
Danilo Salvi
Keyword(s):  
Ambient Temperature ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Heat Recovery ◽  
Power Plants ◽  
Waste Heat ◽  
Cooling System ◽  
Steam Injection ◽  
Maximum Efficiency ◽  
Air Cooling

The steam generated through the use of waste heat recovered from a steam injection gas turbine generally exceeds the maximum mass of steam which can be injected into steam injection gas turbine. The ratio between the steam and air flowing into the engine is not more than 10–15%, as an increase in the pressure ratio can cause the compressor to stall. Naturally, the surplus steam can be utilized for a variety of alternative applications. During the warmer months, the ambient temperature increases and results in reduced thermal efficiency and electrical capacity. An inlet air cooling system for the compressor on a steam injection gas turbine would increase the rating and efficiency of power plants which use this type of equipment. In order to improve the performance of steam injection gas turbines, the authors investigated the option of cooling the intake air to the compressor by harnessing the thermal energy not used to produce the maximum quantity of steam that can be injected into the engine. This alternative use of waste energy makes it possible to reach maximum efficiency in terms of waste recovery. This study examined absorption refrigeration technology, which is one of the various systems adopted to increase efficiency and power rating. The system itself consists of a steam injection gas turbine and a heat recovery and absorption unit, while a computer model was utilized to evaluate the off design performance of the system. The input data required for the model were the following: an operating point, the turbine and compressor curves, the heat recovery and chiller specifications. The performance of an Allison 501 KH steam injection gas plant was analyzed by taking into consideration representative ambient temperature and humidity ranges, the optimal location of the chiller in light of all the factors involved, and which of three possible air cooling systems was the most economically suitable. In order to verify the technical feasibility of the hypothetical model, an economic study was performed on the costs for upgrading the existing steam injection gas cogeneration unit. The results indicate that the estimated pay back period for the project would be four years. In light of these findings, there are clear technical advantages to using gas turbine cogeneration with absorption air cooling in terms of investment.

Development of Next Generation Gas Turbine Combined Cycle System

2016 ◽  
Author(s):  
Hiroyuki Yamazaki ◽  
Yoshiaki Nishimura ◽  
Masahiro Abe ◽  
Kazumasa Takata ◽  
Satoshi Hada ◽  
...  
Keyword(s):  
Power Plant ◽  
Gas Turbines ◽  
Power Plants ◽  
Cooling System ◽  
Combined Cycle ◽  
Air Cooling ◽  
Next Generation ◽  
Air Cooling System ◽  
Forced Air ◽  
Cooling Air

Tohoku Electric Power Company, Inc. (Tohoku-EPCO) has been adopting cutting-edge gas turbines for gas turbine combined cycle (GTCC) power plants to contribute for reduction of energy consumption, and making a continuous effort to study the next generation gas turbines to further improve GTCC power plants efficiency and flexibility. Tohoku-EPCO and Mitsubishi Hitachi Power Systems, Ltd (MHPS) developed “forced air cooling system” as a brand-new combustor cooling system for the next generation GTCC system in a collaborative project. The forced air cooling system can be applied to gas turbines with a turbine inlet temperature (TIT) of 1600deg.C or more by controlling the cooling air temperature and the amount of cooling air. Recently, the forced air cooling system verification test has been completed successfully at a demonstration power plant located within MHPS Takasago Works (T-point). Since the forced air cooling system has been verified, the 1650deg.C class next generation GTCC power plant with the forced air cooling system is now being developed. Final confirmation test of 1650deg.C class next generation GTCC system will be carried out in 2020.

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