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.

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.

New Developments in High Temperature Materials 21 Project in Japan

2005 ◽  
Author(s):  
Hiroshi Harada ◽  
Junzo Fujioka
Keyword(s):  
High Temperature ◽  
Thermal Efficiency ◽  
Gas Turbines ◽  
Power Plants ◽  
Turbine Blades ◽  
Combined Cycle ◽  
Jet Engines ◽  
High Temperature Materials ◽  
Design Program ◽  
Temperature Capability

Following the Kyoto Conference on Climate Change (COP3) held in 1997, the improvement of thermal efficiency in power engineering systems is becoming a major issue. In High Temperature Materials 21 Project at NIMS, materials for turbine blades and vanes are being developed to improve the temperature capability and reduce the CO2 emission of industrial gas turbines (IGT) and jet engines. The target for Ni-base superalloys was set at 1100°C for 1000h creep rupture life under 137MPa to realize ultra-efficient combined cycle power plants and advanced jet engines. A high cost-performance single crystal (SC) superalloy TMS-82+ with 1075°C temperature capability has been developed and tested in a 15MW IGT. A 4th generation SC superalloy TMS-138 exhibiting 1080°C temperature capability has also been developed and tested in a 1650°C test jet engine. TMS-138 is to be applied in the Japanese eco-engine project for 50-seater jet airplanes. A further control of the interfacial dislocation network resulted in a 5th generation SC alloy TMS-162 with 1105°C temperature capability. A virtual gas turbine (VT), which is a combination of materials design program and system design program, is being developed and becoming a powerful tool as an interface between material scientists and system engineers. Using VT, air-cooled blades with our SC superalloys have been evaluated up to 1700°C gas temperature, and a substantial improvement in thermal efficiency of a combined-cycle power generation system has been indicated.

scholarly journals Analysis of the behaviour of biofuel-fired gas turbine power plants

2012 ◽  
Vol 16 (3) ◽  
pp. 849-864 ◽  
Author(s):  
Marcos Escudero ◽  
Ángel Jiménez ◽  
Celina González ◽  
Rafael Nieto ◽  
Ignacio López
Keyword(s):  
Power Generation ◽  
Co2 Emissions ◽  
Gas Turbines ◽  
Power Plants ◽  
Large Scale ◽  
Fossil Fuels ◽  
Technological Development ◽  
Combined Cycle ◽  
Promising Alternative ◽  
Reduction Of Co2

The utilisation of biofuels in gas turbines is a promising alternative to fossil fuels for power generation. It would lead to a significant reduction of CO2 emissions using an existing combustion technology, although considerable changes appear to be required and further technological development is necessary. The goal of this work is to conduct energy and exergy analyses of the behaviour of gas turbines fired with biogas, ethanol and synthesis gas (bio-syngas), compared with natural gas. The global energy transformation process (i.e., from biomass to electricity) also has been studied. Furthermore, the potential reduction of CO2 emissions attained by the use of biofuels has been determined, after considering the restrictions regarding biomass availability. Two different simulation tools have been used to accomplish this work. The results suggest a high interest in, and the technical viability of, the use of Biomass Integrated Gasification Combined Cycle (BioIGCC) systems for large scale power generation.

scholarly journals Boosting Steam Plant Thermal Efficiency and Power Output Through the Addition of Gas Turbines

1987 ◽  
Author(s):  
M. J. J. Linnemeijer ◽  
J. P. van Buijtenen ◽  
A. U. van Loon
Keyword(s):  
Power Output ◽  
Gas Turbines ◽  
Power Plants ◽  
Combined Cycle ◽  
Steam Power ◽  
Power Stations ◽  
Steam Power Plants ◽  
General Terms ◽  
Utility Companies ◽  
Steam Plant

This paper describes the conversion of existing conventional steam power plants into combined cycle plants. A number of Dutch utility companies are currently performing or planning this conversion on their gas-fired power stations, mainly in order to conserve fuel. Modifications of boiler and steam cycle, necessary for the new concept, are presented in general terms, together with a detailed description of one of the projects.

Options to Maximize Power Output for Merchant Plants in Combined Cycle Applications

2001 ◽  
Author(s):  
Rattan Tawney ◽  
Cheryl Pearson ◽  
Mona Brown
Keyword(s):  
Power Output ◽  
Gas Turbines ◽  
Life Cycle Cost ◽  
Peak Power ◽  
Power Plants ◽  
High Reliability ◽  
Combined Cycle ◽  
Cycle Performance ◽  
Plant Design ◽  
Capital Costs

Deregulation and growth in the power industry are causing dramatic changes in power production and distribution. The demand for peak power and potentially high revenues due to premium electricity rates has attracted independent developers to the concept of Merchant Power Plants (MPPs). Over 100,000 MW of greenfield capacity is currently being developed through approximately 200 merchant plants in North America. These MPPs will have no captive customers or long-term power purchase agreements, but will rely on selling electricity into a volatile electricity spot market. Because of this, MPPs need the capability to export as much power as possible on demand. MPPs must also have the capability to produce significant assets in order to compete in the marketplace, based on both technical and commercial operation factors such as value engineering, life-cycle cost management, and information technology. It is no surprise then, that almost all merchant project developers have specified combined cycle (CC) technology. The CC power plant offers the highest thermal efficiency of all electric generating systems commercially available today. It also exhibits low capital costs, low emissions, fuel and operating flexibility, low operation and maintenance costs, short installation schedule, and high reliability/availability. However, since gas turbines (GTs) are the basis for CC power plants, these plants experience power output reductions in the range of 10 to 15 percent during summer months, the period most associated with peak power demand. In order to regain this loss of output as well as to provide additional power to meet peak demands, the most common options are GT inlet fogging, GT steam injection, and heat recovery steam generator (HRSG) supplemental firing. This paper focuses on plant design, cycle performance, and the economics of plant configuration associated with these options. Guidelines are presented in this paper to assist the owner in selecting power enhancement options for the MPP that will maximize their Return on Equity (ROE).

Combined-Cycle Power Plants From Gas Turbines and Geothermal Source Integration

1993 ◽  
Author(s):  
R. Bettocchi ◽  
G. Cantore ◽  
G. Negri di Montenegro ◽  
A. Peretto ◽  
E. Gadda
Keyword(s):  
Power Output ◽  
Gas Turbines ◽  
Power Plants ◽  
High Efficiency ◽  
Combined Cycle ◽  
Point Of View ◽  
Total Power ◽  
Geothermal Fluid ◽  
Exhaust Gases ◽  
Plant Power

Geothermal power plants have difficulties due to the low conversion efficiencies achievable. Geothermal integrated combined cycle proposed and analyzed in this paper is a way to achieve high efficiency. In the proposed cycle the geothermal fluid energy is added, through suitable heat ecxhangers, to that of exhaust gases for generating a steam cycle. The proposed cycle maintains the geothermal fluid segregated from ambient and this can be positive on the environmental point of view. Many systems configurations, based on this possibility, can be taken into account to get the best thermodynamic result. The perfomed analysis examines different possible sharings between the heat coming from geothermal and exhaust gases, and gives the resulting system efficiencies. Various pressures of the geothermal steam and water dominated sources are also taken into account. As a result the analysis shows that the integrated plant power output is largely greater than the total power obtained by summing the gas turbine and the traditional geothermal plant power output, considered separately.

Experimental Study on Low Load Operation Range Extension by Autothermal On-Board Syngas Generation

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Max H. Baumgärtner ◽  
Thomas Sattelmayer
Keyword(s):  
Mass Flow ◽  
Power Output ◽  
Gas Turbines ◽  
Power Plants ◽  
Renewable Energy Sources ◽  
Thermal Power ◽  
Combined Cycle ◽  
Range Extension ◽  
Nox Emissions ◽  
Low Load

Volatile renewable energy sources induce power supply fluctuations. These need to be compensated by flexible conventional power plants. Gas turbines in combined cycle power plants adjust the power output quickly but their turn-down ratio is limited by the slow reaction kinetics, which leads to CO and unburned hydrocarbon emissions. To extend the turn-down ratio, part of the fuel can be converted to syngas, which exhibits a higher reactivity. By an increasing fraction of syngas in the fuel, the reactivity of the mixture is increased and total fuel mass flow and the power output can be reduced. An autothermal on-board syngas generator in combination with two different burner concepts for natural gas (NG)/syngas mixtures was presented in a previous study (Baumgärtner, M. H., and Sattelmayer, T., 2017, “Low Load Operation Range Extension by Autothermal On-Board Syngas Generation,” ASME J. Eng. Gas Turbines Power, 140(4), p. 041505). The study at hand shows a mass-flow variation of the reforming process with mass flows, which allow for pure syngas combustion and further improvements of the two burner concepts which result in a more application-oriented operation. The first of the two burner concepts comprises a generic swirl stage with a central lance for syngas injection. Syngas is injected with swirl to avoid a negative impact on the total swirl intensity and nonswirled. The second concept includes a central swirl stage with an outer ring of jets. For this burner, syngas is injected in both stages to avoid NOx emissions from the swirl stage. Increased NOx emissions produced by NG combustion of the swirl pilot were reported in last year's paper. For both burners, combustion performance is analyzed by OH*-chemiluminescence and gaseous emissions. The lowest possible adiabatic flame temperature without a significant increase of CO emissions was 170–210 K lower for the syngas compared to low load pure NG combustion. This corresponds to a decrease of 15–20% in terms of thermal power.

Second Law Efficiency of the Rankine Bottoming Cycle of a Combined Cycle Power Plant

2008 ◽  
Author(s):  
S. Can Gulen ◽  
Raub W. Smith
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Power Output ◽  
Gas Turbines ◽  
Power Plants ◽  
Combined Cycle ◽  
Cycle Performance ◽  
Second Law ◽  
Modeling Tools ◽  
Combined Cycle Power Plant

A significant portion of the new electrical generating capacity installed in the past decade has employed heavy-duty gas turbines operating in a combined cycle configuration with a steam turbine bottoming cycle. In these power plants approximately one third of the power is generated by the bottoming cycle. To ensure that the highest possible combined cycle efficiency is realized it is important to develop the combined cycle power plant as a system. Doing so requires a solid understanding of the efficiency entitlement of both, topping and bottoming, cycles separately and as a whole. This paper describes a simple but accurate method to estimate the Rankine bottoming cycle power output directly from the gas turbine exhaust exergy utilizing the second law of thermodynamics. The classical first law approach, i.e. the heat and mass balance method, requires lengthy calculations and complex computer-based modeling tools to evaluate Rankine bottoming cycle performance. In this paper, a rigorous application of the fundamental thermodynamic principles embodied by the second law to the major cycle components clearly demonstrates that the Rankine cycle performance can be accurately represented by several key parameters. The power of the second law approach lies in its ability to highlight the theoretical entitlement and state-of-the-art design performances simultaneously via simple, fundamental relationships. By considering economically and technologically feasible upper limits for the key parameters, the maximum achievable bottoming cycle power output is readily calculable for any given gas turbine from its exhaust exergy.

Assessing the Potential of Gas-Recuperation in Reheated Gas Turbines Within Combined Gas-Steam Power Plants

2014 ◽  
Author(s):  
Adam Doligalski ◽  
Luis Sanchez de Leon ◽  
Pavlos K. Zachos ◽  
Vassilios Pachidis
Keyword(s):  
Gas Turbine ◽  
Thermal Efficiency ◽  
Gas Turbines ◽  
Power Plants ◽  
Current Approach ◽  
Combined Cycle ◽  
Variable Position ◽  
Power Turbine ◽  
Power Generation Systems ◽  
Gas Turbine Cycle

This paper presents a comparative analysis between two different gas turbine configurations for implementation within combined cycle power plants, aiming to downselect the most promising one in terms of thermal efficiency at design point. The analysed gas turbines both feature the same dual-pressure steam bottoming cycle, but differ in the gas turbine cycle itself: the first configuration comprises a single-shaft reheated gas turbine with variable position of the reheater (representative of the current approach of the industry to combined cycle power plants), whilst the second configuration comprises a dual-shaft reheated-recuperated engine with free power turbine. Comparison of the two competing gas turbine configurations is conducted by means of systematic exploration of the combined cycle design space. The analysis showed that the reheated-recuperated configuration delivers higher thermal efficiency than the more conventional reheated (non-recuperated) gas turbine and is identified, therefore, as a competitive option for future combined cycle power generation systems.

Sign in / Sign up

Export Citation Format

Share Document