scholarly journals Progress in Modeling and Control of Gas Turbine Power Generation Systems: A Survey

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2358 ◽  
Author(s):  
Omar Mohamed ◽  
Ashraf Khalil

This paper reviews the modeling techniques and control strategies applied to gas turbine power generation plants. Recent modeling philosophies are discussed and the state-of-the-art feasible strategies for control are shown. Research conducted in the field of modeling, simulation, and control of gas turbine power plants has led to notable advancements in gas turbines’ operation and energy efficiency. Tracking recent achievements and trends that have been made is essential for further development and future research. A comprehensive survey is presented here that covers the outdated attempts toward the up-to-date techniques with emphasis on different issues and turbines’ characteristics. Critical review of the various published methodologies is very useful in showing the importance of this research area in practical and technical terms. The different modeling approaches are classified and each category is individually investigated by reviewing a considerable number of research articles. Then, the main features of each category or approach is reported. The modern multi-variable control strategies that have been published for gas turbines are also reviewed. Moreover, future trends are proposed as recommendations for planned research.

2006 ◽  
Vol 128 (2) ◽  
pp. 326-335 ◽  
Author(s):  
R. Bhargava ◽  
M. Bianchi ◽  
F. Melino ◽  
A. Peretto

In recent years, deregulation in the power generation market worldwide combined with significant variation in fuel prices and a need for flexibility in terms of power augmentation specially during periods of high electricity demand (summer months or noon to 6:00 p.m.) has forced electric utilities, cogenerators and independent power producers to explore new power generation enhancement technologies. In the last five to ten years, inlet fogging approach has shown more promising results to recover lost power output due to increased ambient temperature compared to the other available power enhancement techniques. This paper presents the first systematic study on the effects of both inlet evaporative and overspray fogging on a wide range of combined cycle power plants utilizing gas turbines available from the major gas turbine manufacturers worldwide. A brief discussion on the thermodynamic considerations of inlet and overspray fogging including the effect of droplet dimension is also presented. Based on the analyzed systems, the results show that high pressure inlet fogging influences performance of a combined cycle power plant using an aero-derivative gas turbine differently than with an advanced technology or a traditional gas turbine. Possible reasons for the observed differences are discussed.


Author(s):  
Anup Singh

In the 1970s, power generation from gas turbines was minimal. Gas turbines in those days were run on fuel oil, since there was a so-called “natural gas shortage”. The U.S. Fuel Use Act of 1978 essentially disallowed the use of natural gas for power generation. Hence there was no incentive on the part of gas turbine manufacturers to invest in the development of gas turbine technology. There were many regulatory developments in the 1980s and 1990s, which led to the rapid growth in power generation from gas turbines. These developments included Public Utility Regulatory Policy Act of 1978 (encouraging cogeneration), FERC Order 636 (deregulating natural gas industry), Energy Policy Act of 1992 (creating EWGs and IPPs) and FERC Order 888 (open access to electrical transmission system). There was also a backlash from excessive electric rates due to high capital recovery of nuclear and coal-fired plant costs caused by tremendous cost increase resulting from tightening NRC requirements for nuclear plants and significant SO2/NOx/other emissions controls required for coal-fired plants. During this period, rapid technology developments took place in the metallurgy, design, efficiency, and reliability of gas turbines. In addition, U.S. DOE contributed to these developments by encouraging research and development efforts in high temperature and high efficiency gas turbines. Today we are seeing a tremendous explosion of power generating facilities by electric utilities and Independent Power Producers (IPPs). A few years ago, Merchant Power (generation without power purchase agreements) was unheard of. Today it is growing at a very fast pace. Can this rapid growth be sustained? The paper will explore the factors that will play a significant role in the future growth of gas turbine-based power generation in the U.S. The paper will also discuss the methods and developments that could decrease the capital costs of gas turbine power plants resulting in the lowest cost generation compared to other power generation technologies.


Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2935
Author(s):  
Omar Mohamed ◽  
Ashraf Khalil ◽  
Jihong Wang

This paper presents a critical review of the research conducted for modeling and controlling supercritical power plants. Thermal power plants are classified according to the boiler pressure to supercritical and subcritical. The modeling concepts and control strategies of supercritical generation units are far more complex than those of subcritical. On the other hand, supercritical generation technologies are more efficient and much cleaner than subcritical generation units. From a deep technical analysis of the literature, there is no review that is dedicated to models-based control of supercritical power plants and most previous reviews are found to be too general to modeling-based control of fossil fuelled energy sources. This review reports the advancements on modeling and control of supercritical and ultra-supercritical plants as cleaner generation technologies. The various published achievements for modeling supercritical and ultra-supercritical units have been reviewed. The control strategies that fulfill the practical load demand requirements while keeping optimum efficiencies are also reviewed. Finally, expected future directions are reported as recommendations to overcome future challenges. The paper can be used as a brief educational directory to the postgraduate students or future researchers in the field.


Author(s):  
Michael Welch

Combined Cycle Gas Turbine (CCGT) power plant offer operators both environmental and economic benefits. The high efficiency achievable across a wide load range reduces both fuel costs and CO2 emissions to atmosphere. However, the scale of the power generation plays a major role in determining both cost and efficiency: a modern large centralized CCGT of 600MW output or more will have a full load efficiency in excess of 60% and a very competitive installed cost on a US$/kW basis. The smaller gas turbines required for distributed power applications are not optimized for combined cycle operation, with potential full load efficiencies of a combined cycle scheme ranging from a little over 40% to the high 50s depending on the power output of the gas turbine, the exhaust gas conditions and the plant configuration, while the installed cost is around twice that of a large centralized CCGT on a US$/kW basis. The drawback of a conventional combined cycle plant design is the need for water, which is a scarce commodity in some regions. Air cooling of the CCGT plant can be used to reduce water consumption, but make-up water will still be required for the steam system to compensate for steam losses, blowdown etc. While the lower exhaust gas temperatures of the smaller gas turbines impact the combined cycle efficiencies achievable, they do allow Organic Rankine Cycle (ORC) technology to be considered for an alternative combined cycle configuration. This paper compares both the capital and operating costs and performance of combined cycle power plants for distributed power applications in the 30MW to 250MW power range based on conventional steam and various different ORC configurations.


Author(s):  
R. Bhargava ◽  
M. Bianchi ◽  
F. Melino ◽  
A. Peretto

In recent years, deregulation in the power generation market worldwide combined with significant variation in fuel prices and a need for flexibility in terms of power augmentation specially during periods of high electricity demand (summer months or noon to 6 PM) has forced electric utilities, cogenerators and independent power producers to explore new power generation enhancement technologies. In the last 5–10 years, inlet fogging approach has shown more promising results to recover lost power output due to increased ambient temperature compared to the other available power enhancement techniques. This paper presents the first systematic study on the effects of both inlet evaporative and overspray fogging on a wide range of combined cycle power plants utilizing gas turbines available from the major gas turbine manufacturers worldwide. A brief discussion on the thermodynamic considerations of inlet and overspray fogging including the effect of droplet dimension is also presented. Based on the analyzed systems, the results show that high pressure inlet fogging influences performance of a combined cycle power plant using an aero-derivative gas turbine differently than with an advanced technology or a traditional gas turbine. Possible reasons for the observed differences are discussed.


Author(s):  
Steven J. Bossart

The Morgantown Energy Technology Center (METC) of the U.S. Department of Energy (DOE) is actively sponsoring research to develop coal-based power generation systems that use coal more efficiently and economically and with lower emissions than conventional pulverized-coal power plants. Some of the more promising of the advanced coal-based power generation systems are shown in Figure 1: pressurized fluidized-bed combustion combined-cycle (PFBC), integrated gasification combined-cycle (IGCC), and direct coal-fueled turbine (DCFT). These systems rely on gas turbines to produce all or a portion of the electrical power generation. An essential feature of each of these systems is the control of particles at high-temperature and high-pressure (HTHP) conditions. Particle control is needed in all advanced power generation systems to meet environmental regulations and to protect the gas turbine and other major system components. Particles can play a significant role in damaging the gas turbine by erosion, deposition, and corrosion. Erosion is caused by the high-speed impaction of particles on the turbine blades. Particle deposition on the turbine blades can impede gas flow and block cooling air. Particle deposition also contributes to corrosive attack when alkali metal compounds adsorbed on the particles react with the gas turbine blades. Incorporation of HTHP particle control technologies into the advanced power generation systems can reduce gas turbine maintenance requirements, increase plant efficiency, reduce plant capital cost, lower the cost of electricity, reduce wastewater treatment requirements, and eliminate the need for post-turbine particle control to meet New Source Performance Standards (NSPS) for particle emissions.


Author(s):  
Pratyush Nag ◽  
David Little ◽  
Adam Plant ◽  
Douglas Roth

The US gas turbine (GT) power generation market has seen significant volatility in recent years due to climate changes, changes in natural gas prices and the uncertain future of nuclear and coal power generation. Many gas turbine power plants originally intended to operate on a more continuous basis (base load) are operating in intermittent dispatch mode which has caused some operators to frequently shut down their units. This frequent cycling of units can increase start-up and maintenance costs. It could be beneficial to these plants to operate at lower loads when power demand is low and ramp up to higher loads as demand increases. A key issue in operating at lower loads is an increase in carbon monoxide (CO) emissions. When the engines are base loaded, the combustion system operates at high firing temperatures and most of the CO is oxidized to carbon dioxide (CO2). However, at part loads — when the firing temperature is lower — the CO to CO2 oxidation reaction is quenched by the cool regions near the walls of the combustion liner. This results in increased CO emissions at low loads. In order to provide greater operational flexibility to its F- & G-class gas turbine operators, Siemens has developed an upgrade for the engine system designed to allow the gas turbine to operate at lower loads while maintaining emissions. This low load turndown upgrade has been installed, tested and is currently in operation at 8 F and 4 G class Siemens operating gas turbines. These plants were previously operating typically between 70% and 100% of GT base load. Sometimes, when the demand for power was low, typically at night and on weekends, these plants would shut down. During these low power demand periods — with this upgrade installed — these plants continue to operate down to lower loads while maintaining CO emissions and with a capability to more quickly ramp-up to full load when the demand for power increases. This paper details the installation, testing results and continued validation of the Low Load Turndown upgrade.


Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 702 ◽  
Author(s):  
Vitor Jorge ◽  
Roger Granada ◽  
Renan Maidana ◽  
Darlan Jurak ◽  
Guilherme Heck ◽  
...  

Disaster robotics has become a research area in its own right, with several reported cases of successful robot deployment in actual disaster scenarios. Most of these disaster deployments use aerial, ground, or underwater robotic platforms. However, the research involving autonomous boats or Unmanned Surface Vehicles (USVs) for Disaster Management (DM) is currently spread across several publications, with varying degrees of depth, and focusing on more than one unmanned vehicle—usually under the umbrella of Unmanned Marine Vessels (UMV). Therefore, the current importance of USVs for the DM process in its different phases is not clear. This paper presents the first comprehensive survey about the applications and roles of USVs for DM, as far as we know. This work demonstrates that there are few current deployments in disaster scenarios, with most of the research in the area focusing on the technological aspects of USV hardware and software, such as Guidance Navigation and Control, and not focusing on their actual importance for DM. Finally, to guide future research, this paper also summarizes our own contributions, the lessons learned, guidelines, and research gaps.


2018 ◽  
Vol 140 (11) ◽  
Author(s):  
Je-Chin Han

Gas turbines have been extensively used for aircraft engine propulsion, land-based power generation, and industrial applications. Power output and thermal efficiency of gas turbines increase with increasing turbine rotor inlet temperatures (RIT). Currently, advanced gas turbines operate at turbine RIT around 1700 °C far higher than the yielding point of the blade material temperature about 1200 °C. Therefore, turbine rotor blades need to be cooled by 3–5% of high-pressure compressor air around 700 °C. To design an efficient turbine blade cooling system, it is critical to have a thorough understanding of gas turbine heat transfer characteristics within complex three-dimensional (3D) unsteady high-turbulence flow conditions. Moreover, recent research trend focuses on aircraft gas turbines that operate at even higher RIT up to 2000 °C with a limited amount of cooling air, and land-based power generation gas turbines (including 300–400 MW combined cycles with 60% efficiency) burn alternative syngas fuels with higher heat load to turbine components. It is important to understand gas turbine heat transfer problems with efficient cooling strategies under new harsh working environments. Advanced cooling technology and durable thermal barrier coatings (TBCs) play most critical roles for development of new-generation high-efficiency gas turbines with near-zero emissions for safe and long-life operation. This paper reviews basic gas turbine heat transfer issues with advanced cooling technologies and documents important relevant papers for future research references.


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