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).

Study on Effects of Compressor Inlet Air Cooling on GTCC System Performance Under Different Environmental Conditions

2020 ◽  
Author(s):  
Duan Liqiang ◽  
Guo Yaofei ◽  
Pan Pan ◽  
Li Yongxia
Keyword(s):  
Relative Humidity ◽  
Ambient Temperature ◽  
Gas Turbine ◽  
Output Power ◽  
Environmental Conditions ◽  
System Performance ◽  
Combined Cycle ◽  
Air Cooling ◽  
Compressor Inlet ◽  
Cooling Technology

Abstract The environmental conditions (air temperature and relative humidity) have a great impact on the power and efficiency of gas turbine combined cycle (GTCC) system. Using the intake air cooling technology can greatly improve the performance of GTCC system. On the base of the PG9351FA gas turbine combined cycle system, this article builds the models of both the GTCC system and a typical lithium bromide absorption refrigeration system using Aspen Plus software. The effects of compressor inlet air cooling with different environmental conditions on the GTCC system performance are studied. The research results show that using the inlet air cooling technology can obviously increase the output powers of both the gas turbine and the combined cycle power. When the ambient humidity is low, the efficiency of GTCC changes gently; while the ambient humidity is high, the GTCC system efficiency will decline substantially when water in the air is condensed and removed with the progress of cooling process. At the same ambient temperature, when the relative humidity of the environment is equal to 20%, the gas turbine output power is increased by 35.64 MW, with an increase of 16.32%, and the combined cycle output power is increased by 39.57 MW, with an increase of 11.34%. At an ambient temperature of 35°C, for every 2.5 °C drop in the compressor inlet air, the thermal efficiency of the gas turbine increases by 0.189% compared to before cooling.

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.

Inlet Air Cooling Methods for Gas Turbine Based Power Plants

2005 ◽  
Vol 128 (2) ◽  
pp. 312-317 ◽  
Author(s):  
E. Kakaras ◽  
A. Doukelis ◽  
A. Prelipceanu ◽  
S. Karellas
Keyword(s):  
Gas Turbine ◽  
Power Output ◽  
Electricity Generation ◽  
Power Plants ◽  
Evaporative Cooling ◽  
Air Cooling ◽  
Absorption Chiller ◽  
Total Cost ◽  
Evaporative Cooler ◽  
Cooling Methods

Background: Power generation from gas turbines is penalized by a substantial power output loss with increased ambient temperature. By cooling down the gas turbine intake air, the power output penalty can be mitigated. Method of Approach: The purpose of this paper is to review the state of the art in applications for reducing the gas turbine intake air temperature and examine the merits from integration of the different air-cooling methods in gas-turbine-based power plants. Three different intake air-cooling, methods (evaporative cooling, refrigeration cooling, and evaporative cooling of precompressed air) have been applied in two combined cycle power plants and two gas turbine plants. The calculations were performed on a yearly basis of operation, taking into account the time-varying climatic conditions. The economics from integration of the different cooling systems were calculated and compared. Results: The results have demonstrated that the highest incremental electricity generation is realized by absorption intake air-cooling. In terms of the economic performance of the investment, the evaporative cooler has the lowest total cost of incremental electricity generation and the lowest payback period (PB). Concerning the cooling method of pre-compressed air, the results show a significant gain in capacity, but the total cost of incremental electricity generation in this case is the highest. Conclusions: Because of the much higher capacity gain by an absorption chiller system, the evaporative cooler and the absorption chiller system may both be selected for boosting the performance of gas-turbine-based power plants, depending on the prevailing requirements of the plant operator.

Inlet Air Cooling Methods for Gas Turbine Based Power Plants

2004 ◽  
Author(s):  
E. Kakaras ◽  
A. Doukelis ◽  
A. Prelipceanu ◽  
S. Karellas
Keyword(s):  
Gas Turbine ◽  
Power Output ◽  
Gas Turbines ◽  
Power Plants ◽  
Evaporative Cooling ◽  
Climatic Conditions ◽  
Combined Cycle ◽  
Air Cooling ◽  
Cooling Systems ◽  
Cooling Methods

Power generation from gas turbines is penalised by a substantial power output loss with increased ambient temperature. By cooling down the gas turbine intake air, the power output penalty can be mitigated. The purpose of this paper is to review the state of the art in applications for reducing the gas turbine intake air temperature and examine the merits from integration of the different air-cooling methods in gas turbine based power plants. Three different intake air-cooling methods (evaporative cooling, refrigeration cooling and evaporative cooling of pre-compressed air) have been applied in two combined cycle power plants and two gas turbine plants. The calculations were performed on a yearly basis of operation, taking into account the time-varying climatic conditions. The economics from integration of the different cooling systems were calculated and compared.

Combined Cycle Power Augmentation by Inlet Fogging

2005 ◽  
Author(s):  
Hsiao-Wei D. Chiang ◽  
Pai-Yi Wang
Keyword(s):  
Gas Turbine ◽  
Power Output ◽  
Gas Turbines ◽  
Power Plants ◽  
Peak Load ◽  
Combined Cycle ◽  
Augmentation Strategies ◽  
Combined Cycles ◽  
Increasing Demand ◽  
Plant Simulation

Inlet fogging of gas turbine engines has attained considerable popularity due to the ease of installation and the relatively low first cost compared to other inlet cooling methods. With increasing demand for power and with shortages envisioned especially during the peak load times during the summers, there is a need to boost gas turbine power. In Taiwan, most gas turbines operate with combined cycle for base load. Only a small portion operates with simple-cycle for peak load. To recover lost power output due to increased ambient temperature in hot days, the power augmentation strategies for combined-cycles need to be studied in advance. Therefore, the objective is to study the effects caused by adding inlet fogging to an existing gas turbine-based combined-cycle power plant. Simulation runs were made for adding inlet fogging to a combined cycle with two Alstom gas turbines, two heatrecovery steam generators, and one steam turbine. Results show that the power output will be increased by 1% to 5% in typical hot summer days. Since there are seventeen combined-cycle power plants located in different areas in Taiwan, total extra power output gained by inlet fogging can make up the power loss in hot summer days. This paper also includes a parametric study of performance to provide guidelines for combined-cycle power augmentation by inlet fogging.

scholarly journals A Thermodynamic Analysis of Two Competing Mid-Sized Oxyfuel Combustion Combined Cycles

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Egill Thorbergsson ◽  
Tomas Grönstedt
Keyword(s):  
Comparative Analysis ◽  
Gas Turbine ◽  
Power Density ◽  
Thermodynamic Analysis ◽  
Parametric Study ◽  
Pressure Ratio ◽  
Combined Cycle ◽  
Oxyfuel Combustion ◽  
Higher Power ◽  
Combined Cycles

A comparative analysis of two mid-sized oxyfuel combustion combined cycles is performed. The two cycles are the semiclosed oxyfuel combustion combined cycle (SCOC-CC) and the Graz cycle. In addition, a reference cycle was established as the basis for the analysis of the oxyfuel combustion cycles. A parametric study was conducted where the pressure ratio and the turbine entry temperature were varied. The layout and the design of the SCOC-CC are considerably simpler than the Graz cycle while it achieves the same net efficiency as the Graz cycle. The fact that the efficiencies for the two cycles are close to identical differs from previously reported work. Earlier studies have reported around a 3% points advantage in efficiency for the Graz cycle, which is attributed to the use of a second bottoming cycle. This additional feature is omitted to make the two cycles more comparable in terms of complexity. The Graz cycle has substantially lower pressure ratio at the optimum efficiency and has much higher power density for the gas turbine than both the reference cycle and the SCOC-CC.

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.

Performance Improvement of a Supercritical CO2 and Transcritical CO2 Combined Cycle for Offshore Gas Turbine Waste Heat Recovery

2020 ◽  
Author(s):  
Aozheng Zhou ◽  
Xiaodong Ren
Keyword(s):  
Gas Turbine ◽  
Power Output ◽  
Supercritical Co2 ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Net Present Value ◽  
Waste Heat ◽  
Combined Cycle ◽  
Net Power Output ◽  
The Mathematical Model

Abstract The supercritical CO2 (S-CO2) and transcritical CO2 (T-CO2) combined cycle is a promising technology for the waste heat recovery of the offshore gas turbine. In this paper, a new system layout is proposed to investigate the thermodynamic and economic performances improvement of the S-CO2-T-CO2 combined cycle. Compared to the original systems, the residual heat of the topping S-CO2 cycle is recovered and extra recuperation is added to the bottoming T-CO2 cycle. Sensitivity analysis of different systems is carried out based on the mathematical model and multi-objective optimization is conducted. The net power out and the net present value (NPV) are chosen as the objective functions of thermodynamic and economic aspects. The results reveal that at the design point, the improved system has more than 8.23% increment on the net power output and 3.55% increment on the NPV. Besides, the optimized net power output of the improved system attains at least 5.16% increment with 3.15% increment for the optimized NPV at the same time. The improved system can be applied in some practical cases from both the thermodynamic and economic views.

Influence of Water Droplet Size and Temperature on Wet Compression

2007 ◽  
Author(s):  
M. Bianchi ◽  
F. Melino ◽  
A. Peretto ◽  
P. R. Spina ◽  
S. Ingistov
Keyword(s):  
Gas Turbine ◽  
Water Droplet ◽  
Droplet Diameter ◽  
Axial Compressor ◽  
Combined Cycle ◽  
Water Evaporation ◽  
Air Cooling ◽  
Compression Process ◽  
Two Phase ◽  
Wet Compression

In the last years, among all different gas turbine inlet air cooling techniques, an increasing attention to fogging approach is dedicated. The various fogging strategies seem to be a good solution to improve gas turbine or combined cycle produced power with low initial investment cost and less installation downtime. In particular, overspray fogging and interstage injection involve two-phase flow consideration and water evaporation during compression process (also known as wet compression). According to the Author’s knowledge, the field of wet compression is not completely studied and understood. In the present paper, all the principal aspects of wet compression and in particular the influence of injected water droplet diameter and surface temperature, and their effect on gas turbine performance and on the behavior of the axial compressor (change in axial compressor performance map due to the water injection, redistribution of stage load, etc.) are analyzed by using a calculation code, named IN.FO.G.T.E. (INterstage FOgging Gas Turbine Evaluation), developed and validated by the Authors.

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.

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