Steam-Injected GT Cycles Offer More Power in a Hot Season

2003 ◽  
Author(s):  
Kirk Hanawa
Keyword(s):  
Ambient Temperature ◽  
Thermal Energy ◽  
Power Output ◽  
Thermal Efficiency ◽  
Gas Turbines ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Water Steam ◽  
Technology Application ◽  
Cycle Temperature

It is said that gas turbine generating plants on simple cycle reduce the power output by 3% in variation with 1% increase of ambient temperature change. When maintaining maximum cycle temperature, i.e., turbine inlet temperature (T4), the reduction of temperature ratio cannot be avoided by increasing minimum cycle temperature, i.e., ambient temperature (T2). Accordingly, the useful power output must be reduced and the thermal energy would be emitted into the atmosphere. The widely used combined cycle plant is an idea to recover the not-used thermal energy into the power, and it is still losing power by 2% in variation with 1% of the ambient temperature. In order to recover effectively such waste thermal energy into the power output, many ideas are adopted to mainly aim the thermal efficiency exceeding 60%, like “Steam-Cooled Combined Cycle”, “Kalina Cycle” etc. It was confirmed that the water/steam-injected WI/GAS3D GT version of modified LM6000 could produce 106 MW with 56% thermal efficiency at ISO conditions *6, and it is demonstrated, this time, that the power curve of the plant in variation with ambient temperature is very flat, comparing with those of conventional GT plants. It might be recommended to establish advantageous cycle plants using the more advanced gas turbines derived from like GE90, PW4000, and Trent800, in order to get exceeding 60% thermal efficiency in hot climate conditions, and it would be expected that such technology application might contribute to execute the worldwide COP3 agreement by saving the fossil fuel usage, resulting in minimal CO2 emissions.

Genetic Optimization of Steam Injected Gas Turbine Power Plants

2002 ◽  
Author(s):  
Ibrahim Sinan Akmandor ◽  
O¨zhan O¨ksu¨z ◽  
Sec¸kin Go¨kaltun ◽  
Melih Han Bilgin
Keyword(s):  
Gas Turbine ◽  
Power Output ◽  
Thermal Efficiency ◽  
Gas Turbines ◽  
Power Plants ◽  
Pressure Ratio ◽  
Steam Injection ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Compressor Pressure Ratio

A new methodology is developed to find the optimal steam injection levels in simple and combined cycle gas turbine power plants. When steam injection process is being applied to simple cycle gas turbines, it is shown to offer many benefits, including increased power output and efficiency as well as reduced exhaust emissions. For combined cycle power plants, steam injection in the gas turbine, significantly decreases the amount of flow and energy through the steam turbine and the overall power output of the combined cycle is decreased. This study focuses on finding the maximum power output and efficiency of steam injected simple and combined cycle gas turbines. For that purpose, the thermodynamic cycle analysis and a genetic algorithm are linked within an automated design loop. The multi-parameter objective function is either based on the power output or on the overall thermal efficiency. NOx levels have also been taken into account in a third objective function denoted as steam injection effectiveness. The calculations are done for a wide range of parameters such as compressor pressure ratio, turbine inlet temperature, air and steam mass flow rates. Firstly, 6 widely used simple and combined cycle power plants performance are used as test cases for thermodynamic cycle validation. Secondly, gas turbine main parameters are modified to yield the maximum generator power and thermal efficiency. Finally, the effects of uniform crossover, creep mutation, different random number seeds, population size and the number of children per pair of parents on the performance of the genetic algorithm are studied. Parametric analyses show that application of high turbine inlet temperature, high air mass flow rate and no steam injection lead to high power and high combined cycle thermal efficiency. On the contrary, when NOx reduction is desired, steam injection is necessary. For simple cycle, almost full amount of steam injection is required to increase power and efficiency as well as to reduce NOx. Moreover, it is found that the compressor pressure ratio for high power output is significantly lower than the compressor pressure ratio that drives the high thermal efficiency.

Optimum Performance Improvements of the Combined Cycle Based on an Intercooler–Reheated Gas Turbine

2015 ◽  
Vol 137 (6) ◽  
Author(s):  
Thamir K. Ibrahim ◽  
M. M. Rahman
Keyword(s):  
Gas Turbine ◽  
Power Output ◽  
Thermal Efficiency ◽  
Power Plants ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Optimum Level ◽  
Simulation Code ◽  
Operation Conditions ◽  
Turbine Inlet

The performance enhancements and modeling of the gas turbine (GT), together with the combined cycle gas turbine (CCGT) power plant, are described in this study. The thermal analysis has proposed intercooler–reheated-GT (IHGT) configuration of the CCGT system, as well as the development of a simulation code and integrated model for exploiting the CCGT power plants performance, using the matlab code. The validation of a heavy-duty CCGT power plants performance is done through real power plants, namely, MARAFIQ CCGT plants in Saudi Arabia with satisfactory results. The results from this simulation show that the higher thermal efficiency of 56% MW, while high power output of 1640 MW, occurred in IHGT combined cycle plants (IHGTCC), having an optimal turbine inlet temperature about 1900 K. Furthermore, the CCGT system proposed in the study has improved power output by 94%. The results of optimization show that the IHGTCC has optimum power of 1860 MW and thermal efficiency of 59%. Therefore, the ambient temperatures and operation conditions of the CCGT strongly affect their performance. The optimum level of power and efficiency is seen at high turbine inlet temperatures and isentropic turbine efficiency. Thus, it can be understood that the models developed in this study are useful tools for estimating the CCGT power plant's performance.

Technology Application to MHPS Large Flame F Series Gas Turbine

2018 ◽  
Author(s):  
Kiyoshi Fujimoto ◽  
Yuya Fukunaga ◽  
Satoshi Hada ◽  
Toshishige Ai ◽  
Masanori Yuri ◽  
...  
Keyword(s):  
Power Systems ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Environmental Conservation ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
National Project ◽  
Technology Application ◽  
Actual Equipment ◽  
Global Environmental

The development of gas turbines, Mitsubishi Hitachi Power Systems, Ltd. (MHPS) has continued to pursue and contribute to society in terms of global environmental conservation and stable energy supply. MHPS leverages its abundant gas turbine operation experience and takes advantage of its extensive advanced technologies research on the Japanese National Project. MHPS has been participating in this project since 2004. Recent years’ achievements include the demonstration of a gas turbine combined cycle (GTCC) efficiency in excess of 62% created by increasing the turbine inlet temperature to the 1,600°C class in the M501J in 2011. The Latest M701F incorporates “J” gas turbine technologies, already applied to actual equipment, for efficiency improvement. It also applies air-cooled combustor technologies successfully validated in the G class, for increased flexibility. The 1st unit started commercial operation in 2015 and currently 4 units has accumulated more than 46,000 actual operating hours collectively. MHPS is making the upgrading program for existing F-series gas turbines. The proven technology verified in the M501J and developed in the National project increases efficiency and reliability. This paper explains the features and development status of Latest M701F gas turbine, and explains upgrade program for existing F-series gas turbines.

scholarly journals AMBIENT TEMPERATURE IMPACT ON MICRO GAS TURBINES: EXPERIMENTAL CHARACTERIZATION

2018 ◽  
Vol 20 ◽  
pp. 78-85 ◽  
Author(s):  
Iacopo Rossi ◽  
Alberto Traverso
Keyword(s):  
Ambient Temperature ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Engine Performance ◽  
Combined Cycle ◽  
Active Management ◽  
Small Scale ◽  
Inlet Temperature ◽  
Large Power ◽  
Micro Gas Turbine

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 configuration, variation in performance are mitigated by the HRSG and the bottoming steam cycle. In a small scale system, such as a micro gas turbine, the influence on the electric and thermal power productions is strong as well, and is not mitigated by a bottoming cycle. This work focuses on the Turbec T100 micro gas turbine and its performance through a series of operations with different ambient temperatures. The goal is to characterize the engine performance deriving simple correlations for the influence of ambient temperature on performance, at different electrical loads. The newly obtained experimental data are compared with previous performance curves on a modified machine, to capture the differences due to hardware degradation in time. An active management of the compressor inlet temperature may be developed in the future, basing on the analysis reported here.

Performance of a Novel Semiclosed Gas-Turbine Refrigeration Combined Cycle

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Joseph J. Boza ◽  
William E. Lear ◽  
S. A. Sherif
Keyword(s):  
High Pressure ◽  
Ambient Temperature ◽  
Gas Turbine ◽  
Power Output ◽  
Thermal Efficiency ◽  
Combined Cycle ◽  
Water Mixture ◽  
Absorption Refrigeration ◽  
Ambient Conditions ◽  
Large Engine

A thermodynamic performance analysis was performed on a novel cooling and power cycle that combines a semiclosed gas turbine called the high-pressure regenerative turbine engine (HPRTE) with an absorption refrigeration unit. Waste heat from the recirculated combustion gas of the HPRTE is used to power the absorption refrigeration cycle, which cools the high-pressure compressor inlet of the HPRTE to below ambient conditions and also produces excess refrigeration depending on ambient conditions. Two cases were considered: a small engine with a nominal power output of 100kW and a large engine with a nominal power output of 40MW. The cycle was modeled using traditional one-dimensional steady-state thermodynamics, with state-of-the-art polytropic efficiencies and pressure drops for the turbomachinery and heat exchangers, and curve fits for properties of the LiBr-water mixture and the combustion products. The small engine was shown to operate with a thermal efficiency approaching 43% while producing 50% as much 5°C refrigeration as its nominal power output (roughly 50tons) at 30°C ambient conditions. The large engine was shown to operate with a thermal efficiency approaching 62% while producing 25% as much 5°C refrigeration as its nominal power output (roughly 20,000tons) at 30°C ambient conditions. Thermal efficiency stayed relatively constant with respect to ambient temperature for both the large and small engines. It decreased by only 3–4% as the ambient temperature was increased from 10°Cto35°C in each case. The amount of external refrigeration produced by the engine sharply decreased in both engines at around 35°C, eventually reaching zero at roughly 45°C in each case for 5°C refrigeration. However, the evaporator temperature could be raised to 10°C (or higher) to produce external refrigeration in ambient temperatures as high as 50°C.

Aero-Thermodynamic Simulation of a Double-Shaft Industrial Evaporative Gas Turbine

2000 ◽  
Author(s):  
S. M. Camporeale ◽  
B. Fortunato
Keyword(s):  
Ambient Temperature ◽  
Gas Turbine ◽  
Power Output ◽  
Gas Turbines ◽  
Thermodynamic Simulation ◽  
Inlet Temperature ◽  
Part Load ◽  
Design Performance ◽  
Water Rate ◽  
Advanced Cycles

A modeling study has been carried out in order to determine the behavior of evaporative industrial gas turbines power plants at part-load and for varying ambient temperature. On-design and off-design performance have been analyzed by means of a computational program developed for the analysis of advanced cycles. In order to verify the mathematical model and to evaluate the characteristics of up-to-date gas turbine technology, an industrial engine, presently available on the market, has been simulated. A double-shaft gas turbine for power generation has been considered. On-design performance and ratings vs. ambient temperature have been evaluated, with good accordance. It is assumed that, in order to realize a Recuperated Water Injected (RWI) cycle, the industrial gas turbine could be modified, maintaining substantially unchanged the compression system and modifying the turbine blades. The thermodynamic analysis of the cycle has been carried out in order to determine efficiency and power output as a function of the amount of water addition. The RWI cycle gas turbine has been designed and the characteristic maps of the two new turbines have been evaluated. The regulation is performed by means of the simultaneous manipulation of fuel flow rate, water rate, and position of the free turbine nozzle guide vanes (NGV). The regulation criteria, the interaction among the input variables, the safety of the operations (max. turbine inlet temperature, surge limits) and the optimization of the part-load efficiency, are examined and discussed. Ratings as a function of the ambient temperature are examined. The possibility to manipulate the water rate and the position of the NGV in order to provide high efficiency and power output, even on hot days, has been examined. The paper shows that maintaining constant the temperature at the power turbine exit, ratings decrease of 17% in power and 5% in efficiency.

Performance Evaluation of a Gas Turbine Operating Noncontinuously with its Inlet Air Cooled Through an Aquifer Thermal Energy Storage

2006 ◽  
Vol 129 (2) ◽  
pp. 117-124 ◽  
Author(s):  
Farhad Behafarid ◽  
Mehdi N. Bahadori
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Power Output ◽  
Gas Turbines ◽  
Peak Power ◽  
Combined Cycle ◽  
Air Cooling ◽  
Aquifer Thermal Energy Storage ◽  
Cooling Methods

The power output of gas turbines (GT) reduces greatly with the increase of the inlet air temperature. This is a serious problem because gas turbines have been used traditionally to provide electricity during the peak power demands, and the peak power demands in many areas occur on summer afternoons. An aquifer thermal energy storage (ATES) was employed for cooling of the inlet air of the GT. Water from a confined aquifer was cooled in winter and was injected back into the aquifer. The stored chilled water was withdrawn in summer to cool the GT inlet air. The heated water was then injected back into the aquifer. A 20MW GT power plant with 6 and 12h of operation per day, along with a two-well aquifer, was considered for analysis. The purpose of this investigation was to estimate the GT performance improvement. The conventional inlet air cooling methods such as evaporative cooling, fogging and absorption refrigeration were studied and compared with the ATES system. It was shown that for 6h of operation per day, the power output and efficiency of the GT on the warmest day of the year could be increased from 16.5 to 19.7MW and from 31.8% to 34.2%, respectively. The performance of the ATES system was the best among the cooling methods considered on the warmest day of the year. The use of ATES is a viable option for the increase of gas turbines power output and efficiency, provided that suitable confined aquifers are available at their sites. Air cooling in ATES is not dependent on the wet-bulb temperature and therefore can be used in humid areas. This system can also be used in combined cycle power plants.

Parametric Study of Inlet Cooling With Varied COP on Gas Turbine Performance

2014 ◽  
Author(s):  
Maryam Besharati-Givi ◽  
Xianchang Li
Keyword(s):  
Ambient Temperature ◽  
Gas Turbine ◽  
Power Output ◽  
Gas Turbines ◽  
High Efficiency ◽  
Cooling System ◽  
Coefficient Of Performance ◽  
Inlet Temperature ◽  
Turbine Performance ◽  
Compressor Inlet

Gas turbines play an important role in power generation, and it is therefore desired to operate gas turbines with high efficiency and power output. One of the most influential parameters on the performance of a gas turbine is the ambient condition. It is known that inlet cooling can improve the gas turbine performance, especially when the ambient temperature is high. This study examines the effect of inlet cooling with different operating parameters such as compressor inlet temperature, turbine inlet temperature, air fuel ratio, and pressure ratio. Furthermore, the coefficient of performance (COP) of the cooling system is considered a function of the ambient temperature. Aspen Plus software is used to simulate the system under a steady-flow condition. The results indicate that the cooling of the compressor inlet air can substantially improve the power output as well as the overall efficiency of system. More importantly, there exists an optimal temperature at which the inlet cooling should be operated to achieve the highest efficiency.

Performance Potential Analysis of Heavy-Duty Gas Turbines in Combined Cycle Power Plants

2015 ◽  
Author(s):  
Carl Georg Seydel
Keyword(s):  
Co2 Emissions ◽  
Power Output ◽  
Thermal Efficiency ◽  
Gas Turbines ◽  
Power Plants ◽  
Combined Cycle ◽  
Operational Flexibility ◽  
Heavy Duty ◽  
Performance Potential ◽  
Further Development

Within the last decades heavy-duty gas turbines have become more relevant for the energy sector, especially due to the changing requirements on fossil power plants. In combination with high fluctuating renewables, such as wind and solar energy, combined cycle power plants provide the needed operational flexibility along with high thermal efficiency. In order to meet the ambitious reduction targets for future CO2 emissions, the extension of renewable power solutions is mandatory. Meanwhile further development of fossil power plants is important, to ensure a secure energy supply at all conditions and to back up the worldwide increasing power demand. Enhancements for heavy-duty gas turbines focus on higher thermal efficiency and increasing power output, whilst providing a high operational flexibility. This study analyzes the future performance potential for heavy-duty gas turbines in combined cycle power plants, by further development of the main gas turbine components: compressor, combustion chamber and turbine, including the cooling system. The performance potential will be evaluated separately for each component and in combination for on- and off-design operation. The thermodynamic power plant design will be calculated with the performance software GTlab of the German Aerospace Center. Furthermore the fuel and CO2 savings for different levels of component technology development will be quantified. Concluding a potential evolution timeline for combined cycle power plants until the year 2050 will be given. The results show that there is a high potential regarding to thermal efficiency and power output, by conventional component improvements of heavy-duty gas turbines. Also the improved components lead to a significant reduction of fuel consumption and CO2 emissions.

scholarly journals Energy and exergy analyses of a combined cycle power plant with inlet fuel heating

2021 ◽  
pp. 296-296
Author(s):  
Ting Chen ◽  
Anping Wan ◽  
Ke Li ◽  
Xingwei Xiang ◽  
Qinglong Zhou ◽  
...  
Keyword(s):  
Power Plant ◽  
Ambient Temperature ◽  
Power Output ◽  
Thermal Efficiency ◽  
Combined Cycle ◽  
Combined Cycle Power Plant ◽  
Plant System ◽  
Heating Source ◽  
Power Load ◽  
Energy And Exergy

By using exhaust gas as heating source, a combined cycle power plant with inlet fuel heating is investigated experimentally. Energy analysis and exergy analysis are carried out under different power load and ambient temperature. The results reveal that the thermal efficiency of the power plant system increases as power load increases. The thermal efficiency and power output at 5?C are 54.15% and 412 MW, respectively; while when the ambient temperature is 35?C, the thermal efficiency and power output are 52.3% and 330 MW, respectively. Under the same conditions, the combustion chamber has the highest irreversibility rate, while the air compressor has the lowest. The irreversibility rate of the power plant system increases in line with power load. The second-law efficiency increases from 37.08% to 50.12% when the power load changes from 30% to 100%.

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