scholarly journals Modelling of heat transfer and fluid flow in the hot section of gas turbines used in power generation: A comprehensive survey

Author(s):  
Thamasha Samarasinghe ◽  
Chamil Abeykoon ◽  
Ali Turan
Author(s):  
Dieter E. Bohn ◽  
Volker J. Becker ◽  
Karsten A. Kusterer ◽  
Yokiu Otsuki ◽  
Takao Sugimoto ◽  
...  

Modern cooling configurations for turbine blades include complex serpentine-shaped cooling channel geometries for internal-forced convective cooling. The channels are ribbed in order to enhance the convective beat transfer. The design of such cooling configurations is within the power of modem CFD-codes with combined heat transfer analysis in solid body regions. One approach is the conjugate fluid flow and heat transfer solver, CHT-Flow, developed at the Institute of Steam and Gas Turbines, Aachen University of Technology. It takes into account of the mutual influences of internal and external fluid flow and heat transfer. The strategy of the procedure is based on a multi-block-technique and a direct coupling module for fluid flow regions and solid body regions. The configuration under investigation in the present paper is based on a test design of a convective cooled turbine blade with serpentine-shaped cooling passages and cooling gas ejection at the blade tip and the trailing edge. The numerical investigations focus on secondary flow phenomena in the ducts and on the heat transfer analysis at the cooling channel walls. In the first part, the cooling channels are investigated with adiabatic smooth & ribbed walls. The calculations are carried out for the stationary and rotating configuration. Concerning the heat transfer analysis, the results of the ribbed configuration with a fixed thermal boundary condition at the walls in the stationary case are presented. Furthermore, in order to demonstrate the capability of the conjugate method to work without thermal boundary conditions, the cooling configuration is calculated including the external blade flow and the blade walls with internal and external heat transfer under typical operation conditions of gas turbines. The numerical code is used to determine the blade surface temperatures.


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.


1994 ◽  
Vol 47 (8) ◽  
pp. 367-396 ◽  
Author(s):  
Wen-Jei Yang ◽  
Shin Fann ◽  
John H. Kim

Power generation and refrigeration accomplished by means of rotating or reciprocating machinery. One of the basic elements of rotating machinery is the rotating channel system. With the desire for ever increasing efficiency in power generation and refrigeration, higher or lower operating temperatures are achieved. It has provided motivation for the pursuit of knowledge on heat transfer and fluid flow characteristics. This paper reviews the literature pertinent to studies of fluid flow and/or heat transfer in channel flows subjected to radial rotation, parallel rotation, and coaxial revolution. Special problems unique to rotating systems are discussed and future study areas are suggested.


2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Simon Jacobi ◽  
Budimir Rosic

The integrated combustor vane concept for power generation gas turbines with can combustors has been shown to have significant benefits compared to conventional nozzle guide vanes (NGV). Aerodynamic loss, heat transfer levels, and cooling requirements are reduced while stage efficiency is improved by approximately 1.5% (for a no-swirl scenario). Engine realistic combustor flow with swirl, however, leads to increased turning nonuniformity downstream of the integrated vanes. This paper thus illustrates the altered integrated vane stage performance caused by inlet swirl. The study shows a distinct performance penalty for the integrated vane rotor as a result of increased rotor incidence and the rotor's interaction with the residual swirl core. The stage efficiency advantage of the integrated combustor vane concept compared to the conventional design is thus reduced to 0.7%. It is furthermore illustrated how integrated vane profiling is suitable to reduce the turning variation across the span downstream of the vane, further improve stage efficiency (in this case by 0.23%) and thus mitigate the distinct impact of inlet swirl on integrated vane stage performance.


Author(s):  
Minking K. Chyu ◽  
Sean C. Siw ◽  
Ventzislav G. Karaivanov ◽  
William S. Slaughter ◽  
Mary Anne Alvin

Future advanced turbine systems for electric power generation, based on coal-gasified fuels with CO2 capture and sequestration, are aimed for achieving higher cycle efficiency and near-zero emission. The most promising operating cycles being developed are hydrogen-fired cycle and oxyfuel cycle. Both cycles will likely have turbine working fluids significantly different from that of conventional air-based gas turbines. In addition, the oxyfuel cycle will have a turbine inlet temperature target at approximately 2030 K (1760°C), significantly higher than the current level. This suggests that aerothermal control and cooling will play a critical role in realizing our nation’s future fossil power generation systems. This paper provides a computational analysis in comparing the internal cooling performance of a double-wall or skin-cooled airfoil to that of an equivalent serpentine-cooled airfoil. The present results reveal that the double-wall or skin-cooled approach produces superior performance than the conventional serpentine designs. This is particularly effective for the oxyfuel turbine with elevated turbine inlet temperatures. The effects of coolant-side internal heat transfer coefficient on the airfoil metal temperature in both hydrogen-fired and oxyfuel turbines are evaluated. The contribution of thermal barrier coatings toward overall thermal protection for turbine airfoil cooled under these two different cooling configurations is also assessed.


Author(s):  
Simon Jacobi ◽  
Budimir Rosic

The integrated combustor vane concept for power generation gas turbines with can combustors has been shown to have significant benefits compared to conventional nozzle guide vanes. Aerodynamic loss, heat transfer levels and cooling requirements are reduced while stage efficiency is improved by approximately 1.5% (for a no-swirl scenario). Engine realistic combustor flow with swirl however leads to increased turning non-uniformity downstream of the integrated vanes. This paper thus illustrates the altered integrated vane stage performance caused by inlet swirl. The study shows a distinct performance penalty for the integrated vane rotor as a result of increased rotor incidence and the rotor’s interaction with the residual swirl core. The stage efficiency advantage of the integrated combustor vane concept compared to the conventional design is thus reduced to 0.7%. It is furthermore illustrated how integrated vane profiling is suitable to reduce the turning variation across the span downstream of the vane, further improve stage efficiency (in this case by 0.23%) and thus mitigate the distinct impact of inlet swirl on integrated vane stage performance.


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.


2020 ◽  
Vol 170 ◽  
pp. 01019
Author(s):  
Sandeep S Kore ◽  
Sunil V. Dingare ◽  
Satish Chinchanikar ◽  
Pravin Hujare ◽  
Ashok Mache

There are number of applications such as gas turbines, solar air heating, electronics cooling and heat exchangers, where internal cooling passage is observed. For heat transfer augmentation inside these cooling passages different techniques are used like dimpled surface, wings and ribs. Ribs are used in most of the devices for internal cooling. The ribs disturb the boundary layer and increase the turbulent kinetic energy which enhances the heat transfer rate. Most of the researchers concentrate on square and rectangular shaped ribs. The cross section of the rib plays important role in the production of flow field. The shape of ribs affects on boundary layer separation, attachment and hot spots created. In the present paper heat transfer and fluid flow characteristics from rib roughened rectangular duct with different shapes of ribs were investigated. The experimental set up consists of rectangular channel of aspect ratio 4. The pitch to width ratio was varied as 5, 7.5 and 10 respectively. The Reynolds number was varied as 6000 to 30000. The ribs used for the investigations were square, house and boot shaped. From the investigations it is observed that boot shaped rib is having higher thermal performance than other two geometries


Sign in / Sign up

Export Citation Format

Share Document